Commit Graph

968 Commits

Author SHA1 Message Date
Chris Lattner
b3f8397a3d Pull some code out into a function, no functionality change
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@23958 91177308-0d34-0410-b5e6-96231b3b80d8
2005-10-24 06:03:58 +00:00
Chris Lattner
f36aeedaa3 DONT_BUILD_RELINKED is gone and implied by BUILD_ARCHIVE now
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@23940 91177308-0d34-0410-b5e6-96231b3b80d8
2005-10-24 02:26:13 +00:00
Chris Lattner
ab0ed3592b Only build .a file versions of these libraries, instead of .a and .o versions.
This should speed up build times.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@23933 91177308-0d34-0410-b5e6-96231b3b80d8
2005-10-24 01:59:48 +00:00
Chris Lattner
492d4a9d84 Make sure that anything using the ADCE pass pulls in the UnifyFunctionExitNodes
code


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@23931 91177308-0d34-0410-b5e6-96231b3b80d8
2005-10-24 01:40:23 +00:00
Jeff Cohen
66c5fd6c53 When a function takes a variable number of pointer arguments, with a zero
pointer marking the end of the list, the zero *must* be cast to the pointer
type.  An un-cast zero is a 32-bit int, and at least on x86_64, gcc will
not extend the zero to 64 bits, thus allowing the upper 32 bits to be
random junk.

The new END_WITH_NULL macro may be used to annotate a such a function
so that GCC (version 4 or newer) will detect the use of un-casted zero
at compile time.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@23888 91177308-0d34-0410-b5e6-96231b3b80d8
2005-10-23 04:37:20 +00:00
Chris Lattner
63ad7963e4 My previous patch was too conservative. Reject FP and void types, but do
allow pointer types.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@23859 91177308-0d34-0410-b5e6-96231b3b80d8
2005-10-21 05:45:41 +00:00
Chris Lattner
1e9f3af561 Do NOT touch FP ops with LSR. This fixes a testcase Nate sent me from an
inner loop like this:

LBB_RateConvertMono8AltiVec_2:  ; no_exit
        lis r2, ha16(.CPI_RateConvertMono8AltiVec_0)
        lfs f3, lo16(.CPI_RateConvertMono8AltiVec_0)(r2)
        fmr f3, f3
        fadd f0, f2, f0
        fadd f3, f0, f3
        fcmpu cr0, f3, f1
        bge cr0, LBB_RateConvertMono8AltiVec_2  ; no_exit

to an inner loop like this:

LBB_RateConvertMono8AltiVec_1:  ; no_exit
        fsub f2, f2, f1
        fcmpu cr0, f2, f1
        fmr f0, f2
        bge cr0, LBB_RateConvertMono8AltiVec_1  ; no_exit

Doh! good catch!


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@23838 91177308-0d34-0410-b5e6-96231b3b80d8
2005-10-20 04:47:10 +00:00
Chris Lattner
8532cf6258 Make this work for FP constantexprs
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@23773 91177308-0d34-0410-b5e6-96231b3b80d8
2005-10-17 20:18:38 +00:00
Chris Lattner
5e678e03b7 Oops, X+0.0 isn't foldable, but X+-0.0 is.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@23772 91177308-0d34-0410-b5e6-96231b3b80d8
2005-10-17 17:56:38 +00:00
Chris Lattner
560a17d3bc relax this a bit, as we only support the default rounding mode
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@23771 91177308-0d34-0410-b5e6-96231b3b80d8
2005-10-17 17:49:32 +00:00
Chris Lattner
d6155e96f7 Fix (hopefully the last) issue where LSR is nondeterminstic. When pulling
out CSE's of base expressions it could build a result whose order was
nondet.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@23698 91177308-0d34-0410-b5e6-96231b3b80d8
2005-10-11 18:41:04 +00:00
Chris Lattner
7b445c521b Fix another problem where LSR was being nondeterminstic. Also remove elements
from the end of a vector instead of the beginning


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@23697 91177308-0d34-0410-b5e6-96231b3b80d8
2005-10-11 18:30:57 +00:00
Chris Lattner
b4dd1b86fa Fix another lsr-is-nondeterministic case
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@23695 91177308-0d34-0410-b5e6-96231b3b80d8
2005-10-11 18:17:57 +00:00
Chris Lattner
5fb0deb43a Make MaskedValueIsZero a bit more aggressive
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@23677 91177308-0d34-0410-b5e6-96231b3b80d8
2005-10-09 22:08:50 +00:00
Chris Lattner
60de63d0b6 Fix funky xcode indentation
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@23674 91177308-0d34-0410-b5e6-96231b3b80d8
2005-10-09 06:36:35 +00:00
Chris Lattner
a18af06360 Hrm, you didn't see this.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@23673 91177308-0d34-0410-b5e6-96231b3b80d8
2005-10-09 06:24:02 +00:00
Chris Lattner
7305ae28df Fix a source of non-determinism in the backend: the order of processing
IV strides dependend on the pointer order of the strides in memory.
Non-determinism is bad.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@23672 91177308-0d34-0410-b5e6-96231b3b80d8
2005-10-09 06:20:55 +00:00
Jeff Cohen
68d98e0bdc Remove useless variable.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@23656 91177308-0d34-0410-b5e6-96231b3b80d8
2005-10-07 05:28:29 +00:00
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