Commit Graph

1000 Commits

Author SHA1 Message Date
Chris Lattner
5e8ca66914 Make IVUseShouldUsePostIncValue more aggressive when the use is a PHI. In
particular, it should realize that phi's use their values in the pred block
not the phi block itself.  This change turns our em3d loop from this:

_test:
        cmpwi cr0, r4, 0
        bgt cr0, LBB_test_2     ; entry.no_exit_crit_edge
LBB_test_1:     ; entry.loopexit_crit_edge
        li r2, 0
        b LBB_test_6    ; loopexit
LBB_test_2:     ; entry.no_exit_crit_edge
        li r6, 0
LBB_test_3:     ; no_exit
        or r2, r6, r6
        lwz r6, 0(r3)
        cmpw cr0, r6, r5
        beq cr0, LBB_test_6     ; loopexit
LBB_test_4:     ; endif
        addi r3, r3, 4
        addi r6, r2, 1
        cmpw cr0, r6, r4
        blt cr0, LBB_test_3     ; no_exit
LBB_test_5:     ; endif.loopexit.loopexit_crit_edge
        addi r3, r2, 1
        blr
LBB_test_6:     ; loopexit
        or r3, r2, r2
        blr

into:

_test:
        cmpwi cr0, r4, 0
        bgt cr0, LBB_test_2     ; entry.no_exit_crit_edge
LBB_test_1:     ; entry.loopexit_crit_edge
        li r2, 0
        b LBB_test_5    ; loopexit
LBB_test_2:     ; entry.no_exit_crit_edge
        li r6, 0
LBB_test_3:     ; no_exit
        lwz r2, 0(r3)
        cmpw cr0, r2, r5
        or r2, r6, r6
        beq cr0, LBB_test_5     ; loopexit
LBB_test_4:     ; endif
        addi r3, r3, 4
        addi r6, r6, 1
        cmpw cr0, r6, r4
        or r2, r6, r6
        blt cr0, LBB_test_3     ; no_exit
LBB_test_5:     ; loopexit
        or r3, r2, r2
        blr


Unfortunately, this is actually worse code, because the register coallescer
is getting confused somehow.  If it were doing its job right, it could turn the
code into this:

_test:
        cmpwi cr0, r4, 0
        bgt cr0, LBB_test_2     ; entry.no_exit_crit_edge
LBB_test_1:     ; entry.loopexit_crit_edge
        li r6, 0
        b LBB_test_5    ; loopexit
LBB_test_2:     ; entry.no_exit_crit_edge
        li r6, 0
LBB_test_3:     ; no_exit
        lwz r2, 0(r3)
        cmpw cr0, r2, r5
        beq cr0, LBB_test_5     ; loopexit
LBB_test_4:     ; endif
        addi r3, r3, 4
        addi r6, r6, 1
        cmpw cr0, r6, r4
        blt cr0, LBB_test_3     ; no_exit
LBB_test_5:     ; loopexit
        or r3, r6, r6
        blr

... which I'll work on next. :)


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@23604 91177308-0d34-0410-b5e6-96231b3b80d8
2005-10-03 02:50:05 +00:00
Chris Lattner
0ae33eb243 Refactor some code into a function
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@23603 91177308-0d34-0410-b5e6-96231b3b80d8
2005-10-03 01:04:44 +00:00
Chris Lattner
1902ff4d82 This break is bogus and I have no idea why it was there. Basically it prevents
memoizing code when IV's are used by phinodes outside of loops.  In a simple
example, we were getting this code before (note that r6 and r7 are isomorphic
IV's):

        li r6, 0
        or r7, r6, r6
LBB_test_3:     ; no_exit
        lwz r2, 0(r3)
        cmpw cr0, r2, r5
        or r2, r7, r7
        beq cr0, LBB_test_5     ; loopexit
LBB_test_4:     ; endif
        addi r2, r7, 1
        addi r7, r7, 1
        addi r3, r3, 4
        addi r6, r6, 1
        cmpw cr0, r6, r4
        blt cr0, LBB_test_3     ; no_exit

Now we get:

        li r6, 0
LBB_test_3:     ; no_exit
        or r2, r6, r6
        lwz r6, 0(r3)
        cmpw cr0, r6, r5
        beq cr0, LBB_test_6     ; loopexit
LBB_test_4:     ; endif
        addi r3, r3, 4
        addi r6, r2, 1
        cmpw cr0, r6, r4
        blt cr0, LBB_test_3     ; no_exit

this was noticed in em3d.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@23602 91177308-0d34-0410-b5e6-96231b3b80d8
2005-10-03 00:37:33 +00:00
Chris Lattner
37edbf0b21 when checking if we should move a split edge block outside of a loop,
check the presplit pred, not the post-split pred.  This was causing us
to make the wrong decision in some cases, leaving the critical edge block
in the loop.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@23601 91177308-0d34-0410-b5e6-96231b3b80d8
2005-10-03 00:31:52 +00:00
Chris Lattner
fe15830f96 Make the pass name simpler
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@23476 91177308-0d34-0410-b5e6-96231b3b80d8
2005-09-27 21:10:32 +00:00
Chris Lattner
ebe61201d1 Eliminate GetGEPGlobalInitializer in favor of the more powerful
ConstantFoldLoadThroughGEPConstantExpr function in the utils lib.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@23446 91177308-0d34-0410-b5e6-96231b3b80d8
2005-09-26 05:28:52 +00:00
Chris Lattner
363f2a26d5 Factor the GetGEPGlobalInitializer out of this pass and into Transforms/Utils
as ConstantFoldLoadThroughGEPConstantExpr.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@23445 91177308-0d34-0410-b5e6-96231b3b80d8
2005-09-26 05:28:06 +00:00
Chris Lattner
5931c54e85 Move MaskedValueIsZero up.
Match a bunch of idioms for sign extensions, implementing InstCombine/signext.ll


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@23428 91177308-0d34-0410-b5e6-96231b3b80d8
2005-09-24 23:43:33 +00:00
Chris Lattner
7203e158da Refactor this code a bit and make it more general. This now compiles:
struct S { unsigned int i : 6, j : 11, k : 15; } b;
void plus2 (unsigned int x) { b.j += x; }

To:

_plus2:
        lis r2, ha16(L_b$non_lazy_ptr)
        lwz r2, lo16(L_b$non_lazy_ptr)(r2)
        lwz r4, 0(r2)
        slwi r3, r3, 6
        add r3, r4, r3
        rlwimi r3, r4, 0, 26, 14
        stw r3, 0(r2)
        blr


instead of:

_plus2:
        lis r2, ha16(L_b$non_lazy_ptr)
        lwz r2, lo16(L_b$non_lazy_ptr)(r2)
        lwz r4, 0(r2)
        rlwinm r5, r4, 26, 21, 31
        add r3, r5, r3
        rlwimi r4, r3, 6, 15, 25
        stw r4, 0(r2)
        blr

by eliminating an 'and'.

I'm pretty sure this is as small as we can go :)


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@23386 91177308-0d34-0410-b5e6-96231b3b80d8
2005-09-18 07:22:02 +00:00
Chris Lattner
150f12af7f Compile
struct S { unsigned int i : 6, j : 11, k : 15; } b;
void plus2 (unsigned int x) {
  b.j += x;
}

to:

plus2:
        mov %EAX, DWORD PTR [b]
        mov %ECX, %EAX
        and %ECX, 131008
        mov %EDX, DWORD PTR [%ESP + 4]
        shl %EDX, 6
        add %EDX, %ECX
        and %EDX, 131008
        and %EAX, -131009
        or %EDX, %EAX
        mov DWORD PTR [b], %EDX
        ret

instead of:

plus2:
        mov %EAX, DWORD PTR [b]
        mov %ECX, %EAX
        shr %ECX, 6
        and %ECX, 2047
        add %ECX, DWORD PTR [%ESP + 4]
        shl %ECX, 6
        and %ECX, 131008
        and %EAX, -131009
        or %ECX, %EAX
        mov DWORD PTR [b], %ECX
        ret


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@23385 91177308-0d34-0410-b5e6-96231b3b80d8
2005-09-18 06:30:59 +00:00
Chris Lattner
0b7c0bf249 Generalize this transform, using MaskedValueIsZero, allowing us to compile:
struct S { unsigned int i : 6, j : 11, k : 15; } b;
void plus3 (unsigned int x) { b.k += x; }

To:

plus3:
        mov %EAX, DWORD PTR [%ESP + 4]
        shl %EAX, 17
        add DWORD PTR [b], %EAX
        ret

instead of:

plus3:
        mov %EAX, DWORD PTR [%ESP + 4]
        shl %EAX, 17
        mov %ECX, DWORD PTR [b]
        add %EAX, %ECX
        and %EAX, -131072
        and %ECX, 131071
        or %ECX, %EAX
        mov DWORD PTR [b], %ECX
        ret


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@23384 91177308-0d34-0410-b5e6-96231b3b80d8
2005-09-18 06:02:59 +00:00
Chris Lattner
5aa7666ebe fix typeo
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@23383 91177308-0d34-0410-b5e6-96231b3b80d8
2005-09-18 05:25:20 +00:00
Chris Lattner
0d947ea943 Remove unintentionally committed code
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@23382 91177308-0d34-0410-b5e6-96231b3b80d8
2005-09-18 05:12:51 +00:00
Chris Lattner
11021cb988 implement shift.ll:test25. This compiles:
struct S { unsigned int i : 6, j : 11, k : 15; } b;
void plus3 (unsigned int x) {
  b.k += x;
}

to:

_plus3:
        lis r2, ha16(L_b$non_lazy_ptr)
        lwz r2, lo16(L_b$non_lazy_ptr)(r2)
        lwz r3, 0(r2)
        rlwinm r4, r3, 0, 0, 14
        add r4, r4, r3
        rlwimi r4, r3, 0, 15, 31
        stw r4, 0(r2)
        blr

instead of:

_plus3:
        lis r2, ha16(L_b$non_lazy_ptr)
        lwz r2, lo16(L_b$non_lazy_ptr)(r2)
        lwz r4, 0(r2)
        srwi r5, r4, 17
        add r3, r5, r3
        slwi r3, r3, 17
        rlwimi r3, r4, 0, 15, 31
        stw r3, 0(r2)
        blr


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@23381 91177308-0d34-0410-b5e6-96231b3b80d8
2005-09-18 05:12:10 +00:00
Chris Lattner
c8e7756791 Implement add.ll:test29. Codegening:
struct S { unsigned int i : 6, j : 11, k : 15; } b;
void plus1 (unsigned int x) {
  b.i += x;
}

as:
_plus1:
        lis r2, ha16(L_b$non_lazy_ptr)
        lwz r2, lo16(L_b$non_lazy_ptr)(r2)
        lwz r4, 0(r2)
        add r3, r4, r3
        rlwimi r3, r4, 0, 0, 25
        stw r3, 0(r2)
        blr

instead of:

_plus1:
        lis r2, ha16(L_b$non_lazy_ptr)
        lwz r2, lo16(L_b$non_lazy_ptr)(r2)
        lwz r4, 0(r2)
        rlwinm r5, r4, 0, 26, 31
        add r3, r5, r3
        rlwimi r3, r4, 0, 0, 25
        stw r3, 0(r2)
        blr


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@23379 91177308-0d34-0410-b5e6-96231b3b80d8
2005-09-18 04:24:45 +00:00
Chris Lattner
3255bd101d remove debug output
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@23377 91177308-0d34-0410-b5e6-96231b3b80d8
2005-09-18 03:50:25 +00:00
Chris Lattner
e9bed7d107 Implement or.ll:test21. This teaches instcombine to be able to turn this:
struct {
   unsigned int bit0:1;
   unsigned int ubyte:31;
} sdata;

void foo() {
  sdata.ubyte++;
}

into this:

foo:
        add DWORD PTR [sdata], 2
        ret

instead of this:

foo:
        mov %EAX, DWORD PTR [sdata]
        mov %ECX, %EAX
        add %ECX, 2
        and %ECX, -2
        and %EAX, 1
        or %EAX, %ECX
        mov DWORD PTR [sdata], %EAX
        ret


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@23376 91177308-0d34-0410-b5e6-96231b3b80d8
2005-09-18 03:42:07 +00:00
Chris Lattner
6e2f843114 Fix the regression last night compiling povray
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@23348 91177308-0d34-0410-b5e6-96231b3b80d8
2005-09-14 17:32:56 +00:00
Chris Lattner
7835cdde40 Add a simple xform to simplify array accesses with casts in the way.
This is useful for 178.galgel where resolution of dope vectors (by the
optimizer) causes the scales to become apparent.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@23328 91177308-0d34-0410-b5e6-96231b3b80d8
2005-09-13 18:36:04 +00:00
Chris Lattner
396b2baf3c Fix an issue where LSR would miss rewriting a use of an IV expression by a PHI node that is not the original PHI.
This fixes up a dot-product loop in galgel, speeding it up from 18.47s to
16.13s.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@23327 91177308-0d34-0410-b5e6-96231b3b80d8
2005-09-13 02:09:55 +00:00
Chris Lattner
eed48275a1 Add a helper function, allowing us to simplify some code a bit, changing
indentation, no functionality change


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@23325 91177308-0d34-0410-b5e6-96231b3b80d8
2005-09-13 00:40:14 +00:00
Chris Lattner
408902b3c4 Implement a simple xform to turn code like this:
if () { store A -> P; } else { store B -> P; }

into a PHI node with one store, in the most trival case.  This implements
load.ll:test10.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@23324 91177308-0d34-0410-b5e6-96231b3b80d8
2005-09-12 23:23:25 +00:00
Chris Lattner
9c1f0fd8de Another load-peephole optimization: do gcse when two loads are next to
each other.  This implements InstCombine/load.ll:test9


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@23322 91177308-0d34-0410-b5e6-96231b3b80d8
2005-09-12 22:21:03 +00:00
Chris Lattner
62f254df04 Implement a trivial form of store->load forwarding where the store and the
load are exactly consequtive.  This is picked up by other passes, but this
triggers thousands of times in fortran programs that use static locals
(and is thus a compile-time speedup).


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@23320 91177308-0d34-0410-b5e6-96231b3b80d8
2005-09-12 22:00:15 +00:00
Chris Lattner
12b50410cd Fix a regression from last night, which caused this pass to create invalid
code for IV uses outside of loops that are not dominated by the latch block.
We should only convert these uses to use the post-inc value if they ARE
dominated by the latch block.

Also use a new LoopInfo method to simplify some code.

This fixes Transforms/LoopStrengthReduce/2005-09-12-UsesOutOutsideOfLoop.ll


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@23318 91177308-0d34-0410-b5e6-96231b3b80d8
2005-09-12 17:11:27 +00:00
Chris Lattner
c6bae65b49 _test:
li r2, 0
LBB_test_1:     ; no_exit.2
        li r5, 0
        stw r5, 0(r3)
        addi r2, r2, 1
        addi r3, r3, 4
        cmpwi cr0, r2, 701
        blt cr0, LBB_test_1     ; no_exit.2
LBB_test_2:     ; loopexit.2.loopexit
        addi r2, r2, 1
        stw r2, 0(r4)
        blr
[zion ~/llvm]$ cat > ~/xx
Uses of IV's outside of the loop should use hte post-incremented version
of the IV, not the preincremented version.  This helps many loops (e.g. in sixtrack)
which used to generate code like this (this is the code from the
dont-hoist-simple-loop-constants.ll testcase):

_test:
        li r2, 0                 **** IV starts at 0
LBB_test_1:     ; no_exit.2
        or r5, r2, r2            **** Copy for loop exit
        li r2, 0
        stw r2, 0(r3)
        addi r3, r3, 4
        addi r2, r5, 1
        addi r6, r5, 2           **** IV+2
        cmpwi cr0, r6, 701
        blt cr0, LBB_test_1     ; no_exit.2
LBB_test_2:     ; loopexit.2.loopexit
        addi r2, r5, 2       ****  IV+2
        stw r2, 0(r4)
        blr

And now generated code like this:

_test:
        li r2, 1               *** IV starts at 1
LBB_test_1:     ; no_exit.2
        li r5, 0
        stw r5, 0(r3)
        addi r2, r2, 1
        addi r3, r3, 4
        cmpwi cr0, r2, 701     *** IV.postinc + 0
        blt cr0, LBB_test_1
LBB_test_2:     ; loopexit.2.loopexit
        stw r2, 0(r4)          *** IV.postinc + 0
        blr


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@23313 91177308-0d34-0410-b5e6-96231b3b80d8
2005-09-12 06:04:47 +00:00
Chris Lattner
7259df3ab8 implement Transforms/LoopStrengthReduce/dont-hoist-simple-loop-constants.ll.
We used to emit this code for it:

_test:
        li r2, 1     ;; Value tying up a register for the whole loop
        li r5, 0
LBB_test_1:     ; no_exit.2
        or r6, r5, r5
        li r5, 0
        stw r5, 0(r3)
        addi r5, r6, 1
        addi r3, r3, 4
        add r7, r2, r5  ;; should be addi r7, r5, 1
        cmpwi cr0, r7, 701
        blt cr0, LBB_test_1     ; no_exit.2
LBB_test_2:     ; loopexit.2.loopexit
        addi r2, r6, 2
        stw r2, 0(r4)
        blr

now we emit this:

_test:
        li r2, 0
LBB_test_1:     ; no_exit.2
        or r5, r2, r2
        li r2, 0
        stw r2, 0(r3)
        addi r3, r3, 4
        addi r2, r5, 1
        addi r6, r5, 2   ;; whoa, fold those adds!
        cmpwi cr0, r6, 701
        blt cr0, LBB_test_1     ; no_exit.2
LBB_test_2:     ; loopexit.2.loopexit
        addi r2, r5, 2
        stw r2, 0(r4)
        blr

more improvement coming.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@23306 91177308-0d34-0410-b5e6-96231b3b80d8
2005-09-10 01:18:45 +00:00
Chris Lattner
7b4ad94282 Fix a problem that Dan Berlin noticed, where reassociation would not succeed
in building maximal expressions before simplifying them.  In particular, i
cases like this:

X-(A+B+X)

the code would consider A+B+X to be a maximal expression (not understanding
that the single use '-' would be turned into a + later), simplify it (a noop)
then later get simplified again.

Each of these simplify steps is where the cost of reassociation comes from,
so this patch should speed up the already fast pass a bit.

Thanks to Dan for noticing this!


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@23214 91177308-0d34-0410-b5e6-96231b3b80d8
2005-09-02 07:07:58 +00:00
Chris Lattner
2cd85da3ed Avoid creating garbage instructions, just move the old add instruction
to where we need it when converting -(A+B+C) -> -A + -B + -C.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@23213 91177308-0d34-0410-b5e6-96231b3b80d8
2005-09-02 06:38:04 +00:00
Chris Lattner
368a3aabb2 add some assertions and fix problems where reassociate could access the
Ops vector out of range


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@23211 91177308-0d34-0410-b5e6-96231b3b80d8
2005-09-02 05:23:22 +00:00
Chris Lattner
ac83b0301e Fix Regression/Transforms/Reassociate/2005-08-24-Crash.ll
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@23019 91177308-0d34-0410-b5e6-96231b3b80d8
2005-08-24 17:55:32 +00:00
Chris Lattner
8385e51e21 Fix Transforms/LoopStrengthReduce/2005-08-17-OutOfLoopVariant.ll, a crash
on 177.mesa


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@22843 91177308-0d34-0410-b5e6-96231b3b80d8
2005-08-17 21:22:41 +00:00
Chris Lattner
aa96ae780a Use a new helper to split critical edges, making the code simpler.
Do not claim to not change the CFG.  We do change the cfg to split critical
edges.  This isn't causing us a problem now, but could likely do so in the
future.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@22824 91177308-0d34-0410-b5e6-96231b3b80d8
2005-08-17 06:35:16 +00:00
Chris Lattner
80b32b3aab Fix a bad case in gzip where we put lots of things in registers across the
loop, because a IV-dependent value was used outside of the loop and didn't
have immediate-folding capability


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@22798 91177308-0d34-0410-b5e6-96231b3b80d8
2005-08-16 00:38:11 +00:00
Chris Lattner
27e5142309 Ooops, don't forget to clear this. The real inner loop is now:
.LBB_foo_3:     ; no_exit.1
        lfd f2, 0(r9)
        lfd f3, 8(r9)
        fmul f4, f1, f2
        fmadd f4, f0, f3, f4
        stfd f4, 8(r9)
        fmul f3, f1, f3
        fmsub f2, f0, f2, f3
        stfd f2, 0(r9)
        addi r9, r9, 16
        addi r8, r8, 1
        cmpw cr0, r8, r4
        ble .LBB_foo_3  ; no_exit.1


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@22782 91177308-0d34-0410-b5e6-96231b3b80d8
2005-08-13 07:42:01 +00:00
Chris Lattner
934520a747 Recursively scan scev expressions for common subexpressions. This allows us
to handle nested loops much better, for example, by being able to tell that
these two expressions:

{( 8 + ( 16 * ( 1 +  %Tmp11 +  %Tmp12)) +  %c_),+,( 16 *  %Tmp 12)}<loopentry.1>

{(( 16 * ( 1 +  %Tmp11 +  %Tmp12)) +  %c_),+,( 16 *  %Tmp12)}<loopentry.1>

Have the following common part that can be shared:
{(( 16 * ( 1 +  %Tmp11 +  %Tmp12)) +  %c_),+,( 16 *  %Tmp12)}<loopentry.1>

This allows us to codegen an important inner loop in 168.wupwise as:

.LBB_foo_4:     ; no_exit.1
        lfd f2, 16(r9)
        fmul f3, f0, f2
        fmul f2, f1, f2
        fadd f4, f3, f2
        stfd f4, 8(r9)
        fsub f2, f3, f2
        stfd f2, 16(r9)
        addi r8, r8, 1
        addi r9, r9, 16
        cmpw cr0, r8, r4
        ble .LBB_foo_4  ; no_exit.1

instead of:

.LBB_foo_3:     ; no_exit.1
        lfdx f2, r6, r9
        add r10, r6, r9
        lfd f3, 8(r10)
        fmul f4, f1, f2
        fmadd f4, f0, f3, f4
        stfd f4, 8(r10)
        fmul f3, f1, f3
        fmsub f2, f0, f2, f3
        stfdx f2, r6, r9
        addi r9, r9, 16
        addi r8, r8, 1
        cmpw cr0, r8, r4
        ble .LBB_foo_3  ; no_exit.1


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@22781 91177308-0d34-0410-b5e6-96231b3b80d8
2005-08-13 07:27:18 +00:00
Chris Lattner
c60fb08f7e When splitting critical edges, make sure not to leave the new block in the
middle of the loop.  This turns a critical loop in gzip into this:

.LBB_test_1:    ; loopentry
        or r27, r28, r28
        add r28, r3, r27
        lhz r28, 3(r28)
        add r26, r4, r27
        lhz r26, 3(r26)
        cmpw cr0, r28, r26
        bne .LBB_test_8 ; loopentry.loopexit_crit_edge
.LBB_test_2:    ; shortcirc_next.0
        add r28, r3, r27
        lhz r28, 5(r28)
        add r26, r4, r27
        lhz r26, 5(r26)
        cmpw cr0, r28, r26
        bne .LBB_test_7 ; shortcirc_next.0.loopexit_crit_edge
.LBB_test_3:    ; shortcirc_next.1
        add r28, r3, r27
        lhz r28, 7(r28)
        add r26, r4, r27
        lhz r26, 7(r26)
        cmpw cr0, r28, r26
        bne .LBB_test_6 ; shortcirc_next.1.loopexit_crit_edge
.LBB_test_4:    ; shortcirc_next.2
        add r28, r3, r27
        lhz r26, 9(r28)
        add r28, r4, r27
        lhz r25, 9(r28)
        addi r28, r27, 8
        cmpw cr7, r26, r25
        mfcr r26, 1
        rlwinm r26, r26, 31, 31, 31
        add r25, r8, r27
        cmpw cr7, r25, r7
        mfcr r25, 1
        rlwinm r25, r25, 29, 31, 31
        and. r26, r26, r25
        bne .LBB_test_1 ; loopentry

instead of this:

.LBB_test_1:    ; loopentry
        or r27, r28, r28
        add r28, r3, r27
        lhz r28, 3(r28)
        add r26, r4, r27
        lhz r26, 3(r26)
        cmpw cr0, r28, r26
        beq .LBB_test_3 ; shortcirc_next.0
.LBB_test_2:    ; loopentry.loopexit_crit_edge
        add r2, r30, r27
        add r8, r29, r27
        b .LBB_test_9   ; loopexit
.LBB_test_3:    ; shortcirc_next.0
        add r28, r3, r27
        lhz r28, 5(r28)
        add r26, r4, r27
        lhz r26, 5(r26)
        cmpw cr0, r28, r26
        beq .LBB_test_5 ; shortcirc_next.1
.LBB_test_4:    ; shortcirc_next.0.loopexit_crit_edge
        add r2, r11, r27
        add r8, r12, r27
        b .LBB_test_9   ; loopexit
.LBB_test_5:    ; shortcirc_next.1
        add r28, r3, r27
        lhz r28, 7(r28)
        add r26, r4, r27
        lhz r26, 7(r26)
        cmpw cr0, r28, r26
        beq .LBB_test_7 ; shortcirc_next.2
.LBB_test_6:    ; shortcirc_next.1.loopexit_crit_edge
        add r2, r9, r27
        add r8, r10, r27
        b .LBB_test_9   ; loopexit
.LBB_test_7:    ; shortcirc_next.2
        add r28, r3, r27
        lhz r26, 9(r28)
        add r28, r4, r27
        lhz r25, 9(r28)
        addi r28, r27, 8
        cmpw cr7, r26, r25
        mfcr r26, 1
        rlwinm r26, r26, 31, 31, 31
        add r25, r8, r27
        cmpw cr7, r25, r7
        mfcr r25, 1
        rlwinm r25, r25, 29, 31, 31
        and. r26, r26, r25
        bne .LBB_test_1 ; loopentry

Next up, improve the code for the loop.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@22769 91177308-0d34-0410-b5e6-96231b3b80d8
2005-08-12 22:22:17 +00:00
Chris Lattner
e0391beda8 Fix a FIXME: if we are inserting code for a PHI argument, split the critical
edge so that the code is not always executed for both operands.  This
prevents LSR from inserting code into loops whose exit blocks contain
PHI uses of IV expressions (which are outside of loops).  On gzip, for
example, we turn this ugly code:

.LBB_test_1:    ; loopentry
        add r27, r3, r28
        lhz r27, 3(r27)
        add r26, r4, r28
        lhz r26, 3(r26)
        add r25, r30, r28    ;; Only live if exiting the loop
        add r24, r29, r28    ;; Only live if exiting the loop
        cmpw cr0, r27, r26
        bne .LBB_test_5 ; loopexit

into this:

.LBB_test_1:    ; loopentry
        or r27, r28, r28
        add r28, r3, r27
        lhz r28, 3(r28)
        add r26, r4, r27
        lhz r26, 3(r26)
        cmpw cr0, r28, r26
        beq .LBB_test_3 ; shortcirc_next.0
.LBB_test_2:    ; loopentry.loopexit_crit_edge
        add r2, r30, r27
        add r8, r29, r27
        b .LBB_test_9   ; loopexit
.LBB_test_2:    ; shortcirc_next.0
        ...
        blt .LBB_test_1


into this:

.LBB_test_1:    ; loopentry
        or r27, r28, r28
        add r28, r3, r27
        lhz r28, 3(r28)
        add r26, r4, r27
        lhz r26, 3(r26)
        cmpw cr0, r28, r26
        beq .LBB_test_3 ; shortcirc_next.0
.LBB_test_2:    ; loopentry.loopexit_crit_edge
        add r2, r30, r27
        add r8, r29, r27
        b .LBB_t_3:    ; shortcirc_next.0
.LBB_test_3:    ; shortcirc_next.0
        ...
        blt .LBB_test_1


Next step: get the block out of the loop so that the loop is all
fall-throughs again.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@22766 91177308-0d34-0410-b5e6-96231b3b80d8
2005-08-12 22:06:11 +00:00
Chris Lattner
cda9ca5a4f Allow indvar simplify to canonicalize ANY affine IV, not just affine IVs with
constant stride.  This implements Transforms/IndVarsSimplify/variable-stride-ivs.ll


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@22744 91177308-0d34-0410-b5e6-96231b3b80d8
2005-08-10 01:12:06 +00:00
Chris Lattner
50fad70279 Teach LSR to strength reduce IVs that have a loop-invariant but non-constant stride.
For code like this:

void foo(float *a, float *b, int n, int stride_a, int stride_b) {
  int i;
  for (i=0; i<n; i++)
      a[i*stride_a] = b[i*stride_b];
}

we now emit:

.LBB_foo2_2:    ; no_exit
        lfs f0, 0(r4)
        stfs f0, 0(r3)
        addi r7, r7, 1
        add r4, r2, r4
        add r3, r6, r3
        cmpw cr0, r7, r5
        blt .LBB_foo2_2 ; no_exit

instead of:

.LBB_foo_2:     ; no_exit
        mullw r8, r2, r7     ;; multiply!
        slwi r8, r8, 2
        lfsx f0, r4, r8
        mullw r8, r2, r6     ;; multiply!
        slwi r8, r8, 2
        stfsx f0, r3, r8
        addi r2, r2, 1
        cmpw cr0, r2, r5
        blt .LBB_foo_2  ; no_exit

loops with variable strides occur pretty often.  For example, in SPECFP2K
there are 317 variable strides in 177.mesa, 3 in 179.art, 14 in 188.ammp,
56 in 168.wupwise, 36 in 172.mgrid.

Now we can allow indvars to turn functions written like this:

void foo2(float *a, float *b, int n, int stride_a, int stride_b) {
  int i, ai = 0, bi = 0;
  for (i=0; i<n; i++)
    {
      a[ai] = b[bi];
      ai += stride_a;
      bi += stride_b;
    }
}

into code like the above for better analysis.  With this patch, they generate
identical code.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@22740 91177308-0d34-0410-b5e6-96231b3b80d8
2005-08-10 00:45:21 +00:00
Chris Lattner
c41e34520a Fix Regression/Transforms/LoopStrengthReduce/phi_node_update_multiple_preds.ll
by being more careful about updating PHI nodes


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@22739 91177308-0d34-0410-b5e6-96231b3b80d8
2005-08-10 00:35:32 +00:00
Chris Lattner
87265abffc Fix some 80 column violations.
Once we compute the evolution for a GEP, tell SE about it.  This allows users
of the GEP to know it, if the users are not direct.  This allows us to compile
this testcase:

void fbSolidFillmmx(int w, unsigned char *d) {
    while (w >= 64) {
        *(unsigned long long *) (d +  0) = 0;
        *(unsigned long long *) (d +  8) = 0;
        *(unsigned long long *) (d + 16) = 0;
        *(unsigned long long *) (d + 24) = 0;
        *(unsigned long long *) (d + 32) = 0;
        *(unsigned long long *) (d + 40) = 0;
        *(unsigned long long *) (d + 48) = 0;
        *(unsigned long long *) (d + 56) = 0;
        w -= 64;
        d += 64;
    }
}

into:

.LBB_fbSolidFillmmx_2:  ; no_exit
        li r2, 0
        stw r2, 0(r4)
        stw r2, 4(r4)
        stw r2, 8(r4)
        stw r2, 12(r4)
        stw r2, 16(r4)
        stw r2, 20(r4)
        stw r2, 24(r4)
        stw r2, 28(r4)
        stw r2, 32(r4)
        stw r2, 36(r4)
        stw r2, 40(r4)
        stw r2, 44(r4)
        stw r2, 48(r4)
        stw r2, 52(r4)
        stw r2, 56(r4)
        stw r2, 60(r4)
        addi r4, r4, 64
        addi r3, r3, -64
        cmpwi cr0, r3, 63
        bgt .LBB_fbSolidFillmmx_2       ; no_exit

instead of:

.LBB_fbSolidFillmmx_2:  ; no_exit
        li r11, 0
        stw r11, 0(r4)
        stw r11, 4(r4)
        stwx r11, r10, r4
        add r12, r10, r4
        stw r11, 4(r12)
        stwx r11, r9, r4
        add r12, r9, r4
        stw r11, 4(r12)
        stwx r11, r8, r4
        add r12, r8, r4
        stw r11, 4(r12)
        stwx r11, r7, r4
        add r12, r7, r4
        stw r11, 4(r12)
        stwx r11, r6, r4
        add r12, r6, r4
        stw r11, 4(r12)
        stwx r11, r5, r4
        add r12, r5, r4
        stw r11, 4(r12)
        stwx r11, r2, r4
        add r12, r2, r4
        stw r11, 4(r12)
        addi r4, r4, 64
        addi r3, r3, -64
        cmpwi cr0, r3, 63
        bgt .LBB_fbSolidFillmmx_2       ; no_exit


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@22737 91177308-0d34-0410-b5e6-96231b3b80d8
2005-08-09 23:39:36 +00:00
Chris Lattner
b965ee5914 SCEVAddExpr::get() of an empty list is invalid.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@22724 91177308-0d34-0410-b5e6-96231b3b80d8
2005-08-09 01:13:47 +00:00
Chris Lattner
1bbae0cbf2 Implement: LoopStrengthReduce/share_ivs.ll
Two changes:
  * Only insert one PHI node for each stride.  Other values are live in
    values.  This cannot introduce higher register pressure than the
    previous approach, and can take advantage of reg+reg addressing modes.
  * Factor common base values out of uses before moving values from the
    base to the immediate fields.  This improves codegen by starting the
    stride-specific PHI node out at a common place for each IV use.

As an example, we used to generate this for a loop in swim:

.LBB_main_no_exit_2E_6_2E_i_no_exit_2E_7_2E_i_2:        ; no_exit.7.i
        lfd f0, 0(r8)
        stfd f0, 0(r3)
        lfd f0, 0(r6)
        stfd f0, 0(r7)
        lfd f0, 0(r2)
        stfd f0, 0(r5)
        addi r9, r9, 1
        addi r2, r2, 8
        addi r5, r5, 8
        addi r6, r6, 8
        addi r7, r7, 8
        addi r8, r8, 8
        addi r3, r3, 8
        cmpw cr0, r9, r4
        bgt .LBB_main_no_exit_2E_6_2E_i_no_exit_2E_7_2E_i_1

now we emit:

.LBB_main_no_exit_2E_6_2E_i_no_exit_2E_7_2E_i_2:        ; no_exit.7.i
        lfdx f0, r8, r2
        stfdx f0, r9, r2
        lfdx f0, r5, r2
        stfdx f0, r7, r2
        lfdx f0, r3, r2
        stfdx f0, r6, r2
        addi r10, r10, 1
        addi r2, r2, 8
        cmpw cr0, r10, r4
        bgt .LBB_main_no_exit_2E_6_2E_i_no_exit_2E_7_2E_i_1

As another more dramatic example, we used to emit this:

.LBB_main_L_90_no_exit_2E_0_2E_i16_no_exit_2E_1_2E_i19_2:       ; no_exit.1.i19
        lfd f0, 8(r21)
        lfd f4, 8(r3)
        lfd f5, 8(r27)
        lfd f6, 8(r22)
        lfd f7, 8(r5)
        lfd f8, 8(r6)
        lfd f9, 8(r30)
        lfd f10, 8(r11)
        lfd f11, 8(r12)
        fsub f10, f10, f11
        fadd f5, f4, f5
        fmul f5, f5, f1
        fadd f6, f6, f7
        fadd f6, f6, f8
        fadd f6, f6, f9
        fmadd f0, f5, f6, f0
        fnmsub f0, f10, f2, f0
        stfd f0, 8(r4)
        lfd f0, 8(r25)
        lfd f5, 8(r26)
        lfd f6, 8(r23)
        lfd f9, 8(r28)
        lfd f10, 8(r10)
        lfd f12, 8(r9)
        lfd f13, 8(r29)
        fsub f11, f13, f11
        fadd f4, f4, f5
        fmul f4, f4, f1
        fadd f5, f6, f9
        fadd f5, f5, f10
        fadd f5, f5, f12
        fnmsub f0, f4, f5, f0
        fnmsub f0, f11, f3, f0
        stfd f0, 8(r24)
        lfd f0, 8(r8)
        fsub f4, f7, f8
        fsub f5, f12, f10
        fnmsub f0, f5, f2, f0
        fnmsub f0, f4, f3, f0
        stfd f0, 8(r2)
        addi r20, r20, 1
        addi r2, r2, 8
        addi r8, r8, 8
        addi r10, r10, 8
        addi r12, r12, 8
        addi r6, r6, 8
        addi r29, r29, 8
        addi r28, r28, 8
        addi r26, r26, 8
        addi r25, r25, 8
        addi r24, r24, 8
        addi r5, r5, 8
        addi r23, r23, 8
        addi r22, r22, 8
        addi r3, r3, 8
        addi r9, r9, 8
        addi r11, r11, 8
        addi r30, r30, 8
        addi r27, r27, 8
        addi r21, r21, 8
        addi r4, r4, 8
        cmpw cr0, r20, r7
        bgt .LBB_main_L_90_no_exit_2E_0_2E_i16_no_exit_2E_1_2E_i19_1

we now emit:

.LBB_main_L_90_no_exit_2E_0_2E_i16_no_exit_2E_1_2E_i19_2:       ; no_exit.1.i19
        lfdx f0, r21, r20
        lfdx f4, r3, r20
        lfdx f5, r27, r20
        lfdx f6, r22, r20
        lfdx f7, r5, r20
        lfdx f8, r6, r20
        lfdx f9, r30, r20
        lfdx f10, r11, r20
        lfdx f11, r12, r20
        fsub f10, f10, f11
        fadd f5, f4, f5
        fmul f5, f5, f1
        fadd f6, f6, f7
        fadd f6, f6, f8
        fadd f6, f6, f9
        fmadd f0, f5, f6, f0
        fnmsub f0, f10, f2, f0
        stfdx f0, r4, r20
        lfdx f0, r25, r20
        lfdx f5, r26, r20
        lfdx f6, r23, r20
        lfdx f9, r28, r20
        lfdx f10, r10, r20
        lfdx f12, r9, r20
        lfdx f13, r29, r20
        fsub f11, f13, f11
        fadd f4, f4, f5
        fmul f4, f4, f1
        fadd f5, f6, f9
        fadd f5, f5, f10
        fadd f5, f5, f12
        fnmsub f0, f4, f5, f0
        fnmsub f0, f11, f3, f0
        stfdx f0, r24, r20
        lfdx f0, r8, r20
        fsub f4, f7, f8
        fsub f5, f12, f10
        fnmsub f0, f5, f2, f0
        fnmsub f0, f4, f3, f0
        stfdx f0, r2, r20
        addi r19, r19, 1
        addi r20, r20, 8
        cmpw cr0, r19, r7
        bgt .LBB_main_L_90_no_exit_2E_0_2E_i16_no_exit_2E_1_2E_i19_1


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@22722 91177308-0d34-0410-b5e6-96231b3b80d8
2005-08-09 00:18:09 +00:00
Chris Lattner
a553b0cc01 Suck the base value out of the UsersToProcess vector into the BasedUser
class to simplify the code.  Fuse two loops.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@22721 91177308-0d34-0410-b5e6-96231b3b80d8
2005-08-08 22:56:21 +00:00
Chris Lattner
44b807e3c0 Split MoveLoopVariantsToImediateField out from MoveImmediateValues. The
first is a correctness thing, and the later is an optzn thing.  This also
is needed to support a future change.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@22720 91177308-0d34-0410-b5e6-96231b3b80d8
2005-08-08 22:32:34 +00:00
Chris Lattner
4bc5f8071a Use the new 'moveBefore' method to simplify some code. Really, which is
easier to understand?  :)


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@22706 91177308-0d34-0410-b5e6-96231b3b80d8
2005-08-08 19:11:57 +00:00
Chris Lattner
3821e478a5 Not all constants are legal immediates in load/store instructions.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@22704 91177308-0d34-0410-b5e6-96231b3b80d8
2005-08-08 06:25:50 +00:00
Chris Lattner
5272f3c669 Implement LoopStrengthReduce/share_code_in_preheader.ll by having one
rewriter for all code inserted into the preheader, which is never flushed.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@22702 91177308-0d34-0410-b5e6-96231b3b80d8
2005-08-08 05:47:49 +00:00
Chris Lattner
010de25f42 Implement a simple optimization for the termination condition of the loop.
The termination condition actually wants to use the post-incremented value
of the loop, not a new indvar with an unusual base.

On PPC, for example, this allows us to compile
LoopStrengthReduce/exit_compare_live_range.ll to:

_foo:
        li r2, 0
.LBB_foo_1:     ; no_exit
        li r5, 0
        stw r5, 0(r3)
        addi r2, r2, 1
        cmpw cr0, r2, r4
        bne .LBB_foo_1  ; no_exit
        blr

instead of:

_foo:
        li r2, 1                ;; IV starts at 1, not 0
.LBB_foo_1:     ; no_exit
        li r5, 0
        stw r5, 0(r3)
        addi r5, r2, 1
        cmpw cr0, r2, r4
        or r2, r5, r5           ;; Reg-reg copy, extra live range
        bne .LBB_foo_1  ; no_exit
        blr

This implements LoopStrengthReduce/exit_compare_live_range.ll


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@22699 91177308-0d34-0410-b5e6-96231b3b80d8
2005-08-08 05:28:22 +00:00
Chris Lattner
2b83af2d0f Add some simple folds that occur in bitfield cases. Fix a minor bug in
isHighOnes, where it would consider 0 to have high ones.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@22693 91177308-0d34-0410-b5e6-96231b3b80d8
2005-08-07 07:03:10 +00:00
Chris Lattner
4c0e4cdc40 Fix typoCVS: ----------------------------------------------------------------------
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@22692 91177308-0d34-0410-b5e6-96231b3b80d8
2005-08-07 07:00:52 +00:00
Chris Lattner
ce869ee05b * Use the new PHINode::hasConstantValue method to simplify some code
* Teach this code to move allocas out of the loop when tail call eliminating
  a call marked 'tail'.  This implements TailCallElim/move_alloca_for_tail_call.ll
* Do not perform this transformation if a call is marked 'tail' and if there
  are allocas that we cannot move out of the loop in #2.  Doing so would increase
  the stack usage of the function.  This implements fixes
  PR615 and TailCallElim/dont-tce-tail-marked-call.ll.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@22690 91177308-0d34-0410-b5e6-96231b3b80d8
2005-08-07 04:27:41 +00:00
Chris Lattner
9a59fbb896 Make sure to clean CastedPointers after casts are potentially deleted.
This fixes LSR crashes on 301.apsi, 191.fma3d, and 189.lucas


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@22673 91177308-0d34-0410-b5e6-96231b3b80d8
2005-08-05 01:30:11 +00:00
Chris Lattner
68ee736694 now that hasConstantValue defaults to only returning values that dominate
the PHI node, this ugly code can vanish.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@22672 91177308-0d34-0410-b5e6-96231b3b80d8
2005-08-05 01:04:30 +00:00
Nate Begeman
a83ba0f5c9 Fix a fixme in CondPropagate.cpp by moving a PhiNode optimization into
BasicBlock's removePredecessor routine.  This requires shuffling around
the definition and implementation of hasContantValue from Utils.h,cpp into
Instructions.h,cpp


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@22664 91177308-0d34-0410-b5e6-96231b3b80d8
2005-08-04 23:24:19 +00:00
Chris Lattner
26d91f1646 Modify how immediates are removed from base expressions to deal with the fact
that the symbolic evaluator is not always able to use subtraction to remove
expressions.  This makes the code faster, and fixes the last crash on 178.galgel.
Finally, add a statistic to see how many phi nodes are inserted.

On 178.galgel, we get the follow stats:

2562 loop-reduce  - Number of PHIs inserted
3927 loop-reduce  - Number of GEPs strength reduced


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@22662 91177308-0d34-0410-b5e6-96231b3b80d8
2005-08-04 22:34:05 +00:00
Chris Lattner
2114b273ef * Refactor some code into a new BasedUser::RewriteInstructionToUseNewBase
method.
* Fix a crash on 178.galgel, where we would insert expressions before PHI
  nodes instead of into the PHI node predecessor blocks.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@22657 91177308-0d34-0410-b5e6-96231b3b80d8
2005-08-04 20:03:32 +00:00
Chris Lattner
7a2ca56ef3 Fix a case that caused this to crash on 178.galgel
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@22653 91177308-0d34-0410-b5e6-96231b3b80d8
2005-08-04 19:26:19 +00:00
Chris Lattner
7db543f887 Teach LSR about loop-variant expressions, such as loops like this:
for (i = 0; i < N; ++i)
    A[i][foo()] = 0;

here we still want to strength reduce the A[i] part, even though foo() is
l-v.

This also simplifies some of the 'CanReduce' logic.

This implements Transforms/LoopStrengthReduce/ops_after_indvar.ll


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@22652 91177308-0d34-0410-b5e6-96231b3b80d8
2005-08-04 19:08:16 +00:00
Nate Begeman
f08341457f Remove some more dead code.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@22650 91177308-0d34-0410-b5e6-96231b3b80d8
2005-08-04 18:13:56 +00:00
Chris Lattner
3416e5f645 Refactor this code substantially with the following improvements:
1. We only analyze instructions once, guaranteed
  2. AnalyzeGetElementPtrUsers has been ripped apart and replaced with
     something much simpler.

The next step is to handle expressions that are not all indvar+loop-invariant
values (e.g. handling indvar+loopvariant).


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@22649 91177308-0d34-0410-b5e6-96231b3b80d8
2005-08-04 17:40:30 +00:00
Chris Lattner
49f72e68cf refactor some code
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@22643 91177308-0d34-0410-b5e6-96231b3b80d8
2005-08-04 01:19:13 +00:00
Chris Lattner
a4479ad25f invert to if's to make the logic simpler
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@22641 91177308-0d34-0410-b5e6-96231b3b80d8
2005-08-04 00:40:47 +00:00
Chris Lattner
f9186596f0 When processing outer loops and we find uses of an IV in inner loops, make
sure to handle the use, just don't recurse into it.

This permits us to generate this code for a simple nested loop case:

.LBB_foo_0:     ; entry
        stwu r1, -48(r1)
        stw r29, 44(r1)
        stw r30, 40(r1)
        mflr r11
        stw r11, 56(r1)
        lis r2, ha16(L_A$non_lazy_ptr)
        lwz r30, lo16(L_A$non_lazy_ptr)(r2)
        li r29, 1
.LBB_foo_1:     ; no_exit.0
        bl L_bar$stub
        li r2, 1
        or r3, r30, r30
.LBB_foo_2:     ; no_exit.1
        lfd f0, 8(r3)
        stfd f0, 0(r3)
        addi r4, r2, 1
        addi r3, r3, 8
        cmpwi cr0, r2, 100
        or r2, r4, r4
        bne .LBB_foo_2  ; no_exit.1
.LBB_foo_3:     ; loopexit.1
        addi r30, r30, 800
        addi r2, r29, 1
        cmpwi cr0, r29, 100
        or r29, r2, r2
        bne .LBB_foo_1  ; no_exit.0
.LBB_foo_4:     ; return
        lwz r11, 56(r1)
        mtlr r11
        lwz r30, 40(r1)
        lwz r29, 44(r1)
        lwz r1, 0(r1)
        blr

instead of this:

_foo:
.LBB_foo_0:     ; entry
        stwu r1, -48(r1)
        stw r28, 44(r1)                   ;; uses an extra register.
        stw r29, 40(r1)
        stw r30, 36(r1)
        mflr r11
        stw r11, 56(r1)
        li r30, 1
        li r29, 0
        or r28, r29, r29
.LBB_foo_1:     ; no_exit.0
        bl L_bar$stub
        mulli r2, r28, 800           ;; unstrength-reduced multiply
        lis r3, ha16(L_A$non_lazy_ptr)   ;; loop invariant address computation
        lwz r3, lo16(L_A$non_lazy_ptr)(r3)
        add r2, r2, r3
        mulli r4, r29, 800           ;; unstrength-reduced multiply
        addi r3, r3, 8
        add r3, r4, r3
        li r4, 1
.LBB_foo_2:     ; no_exit.1
        lfd f0, 0(r3)
        stfd f0, 0(r2)
        addi r5, r4, 1
        addi r2, r2, 8                 ;; multiple stride 8 IV's
        addi r3, r3, 8
        cmpwi cr0, r4, 100
        or r4, r5, r5
        bne .LBB_foo_2  ; no_exit.1
.LBB_foo_3:     ; loopexit.1
        addi r28, r28, 1               ;;; Many IV's with stride 1
        addi r29, r29, 1
        addi r2, r30, 1
        cmpwi cr0, r30, 100
        or r30, r2, r2
        bne .LBB_foo_1  ; no_exit.0
.LBB_foo_4:     ; return
        lwz r11, 56(r1)
        mtlr r11
        lwz r30, 36(r1)
        lwz r29, 40(r1)
        lwz r28, 44(r1)
        lwz r1, 0(r1)
        blr


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@22640 91177308-0d34-0410-b5e6-96231b3b80d8
2005-08-04 00:14:11 +00:00
Chris Lattner
7a65839f41 Teach loop-reduce to see into nested loops, to pull out immediate values
pushed down by SCEV.

In a nested loop case, this allows us to emit this:

        lis r3, ha16(L_A$non_lazy_ptr)
        lwz r3, lo16(L_A$non_lazy_ptr)(r3)
        add r2, r2, r3
        li r3, 1
.LBB_foo_2:     ; no_exit.1
        lfd f0, 8(r2)        ;; Uses offset of 8 instead of 0
        stfd f0, 0(r2)
        addi r4, r3, 1
        addi r2, r2, 8
        cmpwi cr0, r3, 100
        or r3, r4, r4
        bne .LBB_foo_2  ; no_exit.1

instead of this:

        lis r3, ha16(L_A$non_lazy_ptr)
        lwz r3, lo16(L_A$non_lazy_ptr)(r3)
        add r2, r2, r3
        addi r3, r3, 8
        li r4, 1
.LBB_foo_2:     ; no_exit.1
        lfd f0, 0(r3)
        stfd f0, 0(r2)
        addi r5, r4, 1
        addi r2, r2, 8
        addi r3, r3, 8
        cmpwi cr0, r4, 100
        or r4, r5, r5
        bne .LBB_foo_2  ; no_exit.1


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@22639 91177308-0d34-0410-b5e6-96231b3b80d8
2005-08-03 23:44:42 +00:00
Chris Lattner
be3e5212e2 improve debug output
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@22638 91177308-0d34-0410-b5e6-96231b3b80d8
2005-08-03 23:30:08 +00:00
Chris Lattner
2351abaeab Move from Stage 0 to Stage 1.
Only emit one PHI node for IV uses with identical bases and strides (after
moving foldable immediates to the load/store instruction).

This implements LoopStrengthReduce/dont_insert_redundant_ops.ll, allowing
us to generate this PPC code for test1:

        or r30, r3, r3
.LBB_test1_1:   ; Loop
        li r2, 0
        stw r2, 0(r30)
        stw r2, 4(r30)
        bl L_pred$stub
        addi r30, r30, 8
        cmplwi cr0, r3, 0
        bne .LBB_test1_1        ; Loop

instead of this code:

        or r30, r3, r3
        or r29, r3, r3
.LBB_test1_1:   ; Loop
        li r2, 0
        stw r2, 0(r29)
        stw r2, 4(r30)
        bl L_pred$stub
        addi r30, r30, 8        ;; Two iv's with step of 8
        addi r29, r29, 8
        cmplwi cr0, r3, 0
        bne .LBB_test1_1        ; Loop


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@22635 91177308-0d34-0410-b5e6-96231b3b80d8
2005-08-03 22:51:21 +00:00
Chris Lattner
ec3fb63af2 Rename IVUse to IVUsersOfOneStride, use a struct instead of a pair to
unify some parallel vectors and get field names more descriptive than
"first" and "second".  This isn't lisp afterall :)


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@22633 91177308-0d34-0410-b5e6-96231b3b80d8
2005-08-03 22:21:05 +00:00
Chris Lattner
52d83e66ee Fix a nasty dangling pointer issue. The ScalarEvolution pass would keep a
map from instruction* to SCEVHandles.  When we delete instructions, we have
to tell it about it.  We would run into nasty cases where new instructions
were reallocated at old instruction addresses and get the old map values.
Bad bad bad :(


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@22632 91177308-0d34-0410-b5e6-96231b3b80d8
2005-08-03 21:36:09 +00:00
Chris Lattner
bcd7db59d0 Update to use the new MathExtras.h support for log2 computation.
Patch contributed by Jim Laskey!


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@22592 91177308-0d34-0410-b5e6-96231b3b80d8
2005-08-02 19:16:58 +00:00
Chris Lattner
8105c76da4 Like the comment says, do not insert cast instructions before phi nodes
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@22586 91177308-0d34-0410-b5e6-96231b3b80d8
2005-08-02 03:31:14 +00:00
Chris Lattner
7e608bbb5d add a comment, make a check more lenient
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@22581 91177308-0d34-0410-b5e6-96231b3b80d8
2005-08-02 02:52:02 +00:00
Chris Lattner
e9100c69cb Simplify for loop, clear a per-loop map after processing each loop
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@22580 91177308-0d34-0410-b5e6-96231b3b80d8
2005-08-02 02:44:31 +00:00
Chris Lattner
07cd0ff298 Add a comment
Make LSR ignore GEP's that have loop variant base values, as we currently
cannot codegen them


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@22576 91177308-0d34-0410-b5e6-96231b3b80d8
2005-08-02 01:32:29 +00:00
Chris Lattner
1060e09fb2 Fix an iterator invalidation problem
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@22575 91177308-0d34-0410-b5e6-96231b3b80d8
2005-08-02 00:41:11 +00:00
Jeff Cohen
d29b6aa608 Keep tabs and trailing spaces out.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@22565 91177308-0d34-0410-b5e6-96231b3b80d8
2005-07-30 18:33:25 +00:00
Jeff Cohen
cfb1d4235f Fix VC++ build problems.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@22564 91177308-0d34-0410-b5e6-96231b3b80d8
2005-07-30 18:22:27 +00:00
Nate Begeman
f84d5ab5df Ack, typo
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@22560 91177308-0d34-0410-b5e6-96231b3b80d8
2005-07-30 00:21:31 +00:00
Nate Begeman
1699748567 Commit a new LoopStrengthReduce pass that can use scalar evolutions and
target data to decide which loop induction variables to strength reduce
and how to do so.  This work is mostly by Chris Lattner, with tweaks by
me to get it working on some of MultiSource.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@22558 91177308-0d34-0410-b5e6-96231b3b80d8
2005-07-30 00:15:07 +00:00
Nate Begeman
36f891bdf6 Break SCEVExpander out of IndVarSimplify into its own .h/.cpp file so that
other passes may use it.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@22557 91177308-0d34-0410-b5e6-96231b3b80d8
2005-07-30 00:12:19 +00:00
Jeff Cohen
00b16889ab Eliminate all remaining tabs and trailing spaces.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@22523 91177308-0d34-0410-b5e6-96231b3b80d8
2005-07-27 06:12:32 +00:00
Chris Lattner
f9944f109c Do not let MaskedValueIsZero consider undef to be zero, for reasons
explained in the comment.

This fixes UnitTests/2003-09-18-BitFieldTest on darwin


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@22483 91177308-0d34-0410-b5e6-96231b3b80d8
2005-07-20 18:49:28 +00:00
Chris Lattner
7911f03626 When transforming &A[i] < &A[j] -> i < j, make sure to perform the comparison
as a signed compare.  This patch may fix PR597, but is correct in any case.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@22465 91177308-0d34-0410-b5e6-96231b3b80d8
2005-07-18 23:07:33 +00:00
Chris Lattner
b3d59701c8 Fix a problem that instcombine would hit when dealing with unreachable code.
Because the instcombine has to scan the entire function when it starts up
to begin with, we might as well do it in DFO so we can nuke unreachable code.

This fixes: Transforms/InstCombine/2005-07-07-DeadPHILoop.ll


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@22348 91177308-0d34-0410-b5e6-96231b3b80d8
2005-07-07 20:40:38 +00:00
Andrew Lenharth
38b5807bd9 prevent va_arg from being hoisted from a loop
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@22265 91177308-0d34-0410-b5e6-96231b3b80d8
2005-06-20 13:36:33 +00:00
Andrew Lenharth
558bc88a00 core changes for varargs
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@22254 91177308-0d34-0410-b5e6-96231b3b80d8
2005-06-18 18:34:52 +00:00
Reid Spencer
4b828e6384 Clean up some uninitialized variables and missing return statements that
GCC 4.0.0 compiler (sometimes incorrectly) warns about under release build.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@22249 91177308-0d34-0410-b5e6-96231b3b80d8
2005-06-18 17:37:34 +00:00
Chris Lattner
e88b7533be This is not true: (X != 13 | X < 15) -> X < 15
It is actually always true.  This fixes PR586 and
Transforms/InstCombine/2005-06-16-SetCCOrSetCCMiscompile.ll


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@22236 91177308-0d34-0410-b5e6-96231b3b80d8
2005-06-17 03:59:17 +00:00
Chris Lattner
5662503afd Don't crash when dealing with INTMIN. This fixes PR585 and
Transforms/InstCombine/2005-06-16-RangeCrash.ll


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@22234 91177308-0d34-0410-b5e6-96231b3b80d8
2005-06-17 02:05:55 +00:00
Chris Lattner
d7e31cfaae avoid constructing out of range shift amounts.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@22230 91177308-0d34-0410-b5e6-96231b3b80d8
2005-06-17 01:29:28 +00:00
Chris Lattner
f9c775c22e Fix PR583 and testcase Transforms/InstCombine/2005-06-15-DivSelectCrash.ll
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@22227 91177308-0d34-0410-b5e6-96231b3b80d8
2005-06-16 04:55:52 +00:00
Chris Lattner
8d7089e1d5 Fix PR571, removing code that does just the WRONG thing :)
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@22225 91177308-0d34-0410-b5e6-96231b3b80d8
2005-06-16 03:00:08 +00:00
Chris Lattner
aa457ac2e7 Fix a bug in my previous patch. Do not get the shift amount type (which
is always ubyte, get the type being shifted).  This unbreaks espresso


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@22224 91177308-0d34-0410-b5e6-96231b3b80d8
2005-06-16 01:52:07 +00:00
Chris Lattner
4bd09d70cc Fix PR582. The rewriter can move casts around, which invalidated the
BB iterator.  This fixes Transforms/IndVarsSimplify/2005-06-15-InstMoveCrash.ll


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@22221 91177308-0d34-0410-b5e6-96231b3b80d8
2005-06-15 21:29:31 +00:00
Chris Lattner
e17a128a55 Fix PR577 and testcase InstCombine/2005-06-15-ShiftSetCCCrash.ll.
Do not perform undefined out of range shifts.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@22217 91177308-0d34-0410-b5e6-96231b3b80d8
2005-06-15 20:53:31 +00:00
Reid Spencer
877c3e2b81 Put the hack back in that removes features, causes regressions to fail, but
allows test programs to succeed. Actual fix for this is forthcoming.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@22213 91177308-0d34-0410-b5e6-96231b3b80d8
2005-06-15 18:25:30 +00:00
Reid Spencer
16b5644f04 Unbreak several InstCombine regression checks introduced by a hack to
fix the bzip2 test. A better hack is needed.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@22209 91177308-0d34-0410-b5e6-96231b3b80d8
2005-06-13 06:41:26 +00:00
Andrew Lenharth
837be1ec35 hack to fix bzip2 (bug 571)
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@22192 91177308-0d34-0410-b5e6-96231b3b80d8
2005-06-04 12:43:56 +00:00
Chris Lattner
e43702695d preserve calling conventions when hacking on code
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@22024 91177308-0d34-0410-b5e6-96231b3b80d8
2005-05-14 12:25:32 +00:00