Commit Graph

238 Commits

Author SHA1 Message Date
Chris Lattner
ac0b6ae358 Detemplatize the Statistic class. The only type it is instantiated with
is 'unsigned'.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@32279 91177308-0d34-0410-b5e6-96231b3b80d8
2006-12-06 17:46:33 +00:00
Chris Lattner
4b10591265 Don't transform in another bad case: if the block is empty, it should be
simplified before we do this xform so that our cost model is accurate.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@31864 91177308-0d34-0410-b5e6-96231b3b80d8
2006-11-18 22:25:39 +00:00
Chris Lattner
f10a56a86f Fix another case we *don't* want to do this xform.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@31861 91177308-0d34-0410-b5e6-96231b3b80d8
2006-11-18 21:56:39 +00:00
Chris Lattner
154e104718 make the previous change more aggressive, moving any block with no fallthrough.
This speeds up yacr2 by 7% on a core2.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@31856 91177308-0d34-0410-b5e6-96231b3b80d8
2006-11-18 21:30:35 +00:00
Chris Lattner
a7bef4a4e4 Minor code layout tweak: if we have something like this:
if (cond) goto BB2
BB1:
    ...
    return;
BB2:
   ...

Move BB1 to the end of the function so that the code falls through in the
non-return case.  This has the effect of moving assert (and other no-return
call) bodies and return blocks out of loops.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@31855 91177308-0d34-0410-b5e6-96231b3b80d8
2006-11-18 20:47:54 +00:00
Chris Lattner
5d056952ba optimize single MBB loops better. In particular, produce:
LBB1_57:        #bb207.i
        movl 72(%esp), %ecx
        movb (%ecx,%eax), %cl
        movl 80(%esp), %edx
        movb %cl, 1(%edx,%eax)
        incl %eax
        cmpl $143, %eax
        jne LBB1_57     #bb207.i
        jmp LBB1_64     #cond_next255.i

intead of:

LBB1_57:        #bb207.i
        movl 72(%esp), %ecx
        movb (%ecx,%eax), %cl
        movl 80(%esp), %edx
        movb %cl, 1(%edx,%eax)
        incl %eax
        cmpl $143, %eax
        je LBB1_64      #cond_next255.i
        jmp LBB1_57     #bb207.i

This eliminates a branch per iteration of the loop.  This hurted PPC
particularly, because the extra branch meant another dispatch group for each
iteration of the loop.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@31530 91177308-0d34-0410-b5e6-96231b3b80d8
2006-11-08 01:03:21 +00:00
Jeff Cohen
d41b30def3 Unbreak VC++ build.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@31464 91177308-0d34-0410-b5e6-96231b3b80d8
2006-11-05 19:31:28 +00:00
Reid Spencer
3ed469ccd7 For PR786:
Turn on -Wunused and -Wno-unused-parameter. Clean up most of the resulting
fall out by removing unused variables. Remaining warnings have to do with
unused functions (I didn't want to delete code without review) and unused
variables in generated code. Maintainers should clean up the remaining
issues when they see them. All changes pass DejaGnu tests and Olden.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@31380 91177308-0d34-0410-b5e6-96231b3b80d8
2006-11-02 20:25:50 +00:00
Chris Lattner
d4bf3c2fd6 give branch folding a simple heuristic to decide which block to split so that
it inserts an uncond branch where it is less likely to cause a problem.  This
fixes some perf issues on ppc.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@31354 91177308-0d34-0410-b5e6-96231b3b80d8
2006-11-01 19:36:29 +00:00
Chris Lattner
1d08d83230 make tail merging more aggressive. If two blocks share a common tail, but the
tail is not an entire block for either of them, pick one, split it, then
merge the common part.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@31336 91177308-0d34-0410-b5e6-96231b3b80d8
2006-11-01 01:16:12 +00:00
Chris Lattner
d8ccff0c3e enable branch folding with an option
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@31335 91177308-0d34-0410-b5e6-96231b3b80d8
2006-11-01 00:38:31 +00:00
Chris Lattner
6b0e3f8907 Make CanFallThrough more intelligent (so it can handle blocks with (e.g.) no
successors), and make island block movement more general.

This compiles CodeGen/X86/2006-04-27-ISelFoldingBug.ll to:

_loadAndRLEsource_no_exit_2E_1_label_2E_0:
        subl $8, %esp
        movl %esi, 4(%esp)
        movl %ebx, (%esp)
        movl 16(%esp), %eax
        movl 12(%esp), %ecx
LBB1_3: #label.0
        movl _last, %edx
        movl %edx, %esi
        incl %esi
        movl %esi, _last
        movl %ecx, %ebx
        # TRUNCATE movb %bl, %bl
        movl _block, %esi
        movb %bl, 1(%esi,%edx)
        cmpl %eax, _last
        jge LBB1_2      #codeRepl5.exitStub
LBB1_4: #label.0
        cmpl $257, %ecx
        je LBB1_2       #codeRepl5.exitStub
LBB1_1: #label.0.no_exit.1_crit_edge.exitStub
        movl $1, %eax
        movl (%esp), %ebx
        movl 4(%esp), %esi
        addl $8, %esp
        ret
LBB1_2: #codeRepl5.exitStub
        xorl %eax, %eax
        movl (%esp), %ebx
        movl 4(%esp), %esi
        addl $8, %esp
        ret

instead of:

_loadAndRLEsource_no_exit_2E_1_label_2E_0:
        subl $8, %esp
        movl %esi, 4(%esp)
        movl %ebx, (%esp)
        movl 16(%esp), %eax
        movl 12(%esp), %ecx
        jmp LBB1_3      #label.0
LBB1_1: #label.0.no_exit.1_crit_edge.exitStub
        movl $1, %eax
        movl (%esp), %ebx
        movl 4(%esp), %esi
        addl $8, %esp
        ret
LBB1_2: #codeRepl5.exitStub
        xorl %eax, %eax
        movl (%esp), %ebx
        movl 4(%esp), %esi
        addl $8, %esp
        ret
LBB1_3: #label.0
        movl _last, %edx
        movl %edx, %esi
        incl %esi
        movl %esi, _last
        movl %ecx, %ebx
        # TRUNCATE movb %bl, %bl
        movl _block, %esi
        movb %bl, 1(%esi,%edx)
        cmpl %eax, _last
        jge LBB1_2      #codeRepl5.exitStub
LBB1_4: #label.0
        cmpl $257, %ecx
        jne LBB1_1      #label.0.no_exit.1_crit_edge.exitStub
        jmp LBB1_2      #codeRepl5.exitStub

... which is much better layout :)


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@31282 91177308-0d34-0410-b5e6-96231b3b80d8
2006-10-29 21:05:41 +00:00
Chris Lattner
6acfe12dd6 Teach branch folding to fold identical jump tables together and to delete
jump tables that are dead.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@31273 91177308-0d34-0410-b5e6-96231b3b80d8
2006-10-28 18:34:47 +00:00
Chris Lattner
cf420cca57 improve deletion of blocks that just contain branches by knowing that
the pred block doesn't fall through into them if it's a jumptable.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@31263 91177308-0d34-0410-b5e6-96231b3b80d8
2006-10-28 17:32:47 +00:00
Chris Lattner
c2e91e34dc simplify code
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@31188 91177308-0d34-0410-b5e6-96231b3b80d8
2006-10-25 22:21:37 +00:00
Chris Lattner
323ece6fcd turn off tail merging for now
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@31180 91177308-0d34-0410-b5e6-96231b3b80d8
2006-10-25 18:08:50 +00:00
Chris Lattner
7d09784d3f move single basic blocks that are neither fallen into nor fall out of into
a place more useful.  In particular, if we can put them in a place where code
will be able to fall into it, do so.  Otherwise, put it in a place it can fall
through into a successor.  Otherwise, if preventing a fallthrough, move to the
end of the function, out of the way.

This deletes several hundred unconditional branches from spass.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@31149 91177308-0d34-0410-b5e6-96231b3b80d8
2006-10-24 01:12:32 +00:00
Chris Lattner
a4bcfe12d1 Enable tail merging by default.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@31140 91177308-0d34-0410-b5e6-96231b3b80d8
2006-10-23 22:10:12 +00:00
Jim Laskey
66ebf0973d More complete solution to deleting blocks and debug info.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@31129 91177308-0d34-0410-b5e6-96231b3b80d8
2006-10-23 14:56:37 +00:00
Chris Lattner
4bc135e93b don't break infinite loops
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@31102 91177308-0d34-0410-b5e6-96231b3b80d8
2006-10-21 06:11:43 +00:00
Chris Lattner
a2d799531a Use branch reversal to do stuff like this:
call L_strcmp$stub
        testl %eax, %eax
-       jne LBB26_208   #cond_true6020
-       jmp LBB26_227   #bb7119
+       je LBB26_227    #bb7119
 LBB26_208:     #cond_true6020
        movl $l31_str14, 4(%esp)

        testl %eax, %eax
-       jne LBB26_704   #cond_true13042
-       jmp LBB26_713   #bb13151
+       je LBB26_713    #bb13151
 LBB26_704:     #cond_true13042
        movl $_str52, 4(%esp)

        cmpl 76(%ecx), %eax
-       jge LBB26_1628  #cond_false63.i.i
-       jmp LBB26_1769  #_Z8makeGridP13mrSurfaceListidiidd.exit.i
+       jl LBB26_1769   #_Z8makeGridP13mrSurfaceListidiidd.exit.i
 LBB26_1628:    #cond_false63.i.i
        movl $0, 48964(%esp)


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@31100 91177308-0d34-0410-b5e6-96231b3b80d8
2006-10-21 05:54:00 +00:00
Chris Lattner
2d47bd937c Transform code like:
jle FOO
  jmp BAR
BAR:

into:

  jle FOO
BAR:

... whoa!


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@31098 91177308-0d34-0410-b5e6-96231b3b80d8
2006-10-21 05:43:30 +00:00
Chris Lattner
386e29065d Three changes:
1. Remove a bunch of ifdef'd code.
2. When a block just contains an uncond branch, change all blocks branching
   to it to jump to the destination instead.
3. If branch analysis tells us some edges in the machinecfg are not actually
   possible, remove them.

#2 triggers a suprisingly large number of times.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@31094 91177308-0d34-0410-b5e6-96231b3b80d8
2006-10-21 05:08:28 +00:00
Chris Lattner
12143054aa Add an experimental cross-jumping implementation.
This is currently disabled by default and limited in several ways, but does
have a positive effect.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@31090 91177308-0d34-0410-b5e6-96231b3b80d8
2006-10-21 00:47:49 +00:00
Chris Lattner
683747abb8 Teach the branch folder to update debug info if it removes blocks with line
# notes in it.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@31026 91177308-0d34-0410-b5e6-96231b3b80d8
2006-10-17 23:17:27 +00:00
Chris Lattner
ffddf6ba1c Enable deleting branches to successor blocks. With the previous patches,
branch folding can now compile stuff like this:

void foo(int W, int X, int Y, int Z) {
  if (W & 1) {
    for (; X;--X) bar();
  } else if (W & 2) {
    for (; Y;--Y) bar();
  } else if (W & 4) {
    for (; Z;--Z) bar();
  } else if (W & 8) {
    for (; W;--W) bar();
  }

  if (W) {
    bar();
  }
}

contrived testcase where loops exits all end up merging together.  To have
the loop merges be:

...
        cmplw cr0, r30, r27
        bne cr0, LBB1_14        ;bb38
LBB1_16:        ;cond_next48.loopexit
        mr r27, r29
LBB1_20:        ;cond_next48
        cmplwi cr0, r27, 0
        beq cr0, LBB1_22        ;UnifiedReturnBlock
...

instead of:


...
        cmplw cr0, r30, r27
        bne cr0, LBB1_14        ;bb38
LBB1_16:        ;cond_next48.loopexit
        mr r27, r29
        b LBB1_20       ;cond_next48
LBB1_17:        ;cond_next48.loopexit1
        b LBB1_20       ;cond_next48
LBB1_18:        ;cond_next48.loopexit2
        b LBB1_20       ;cond_next48
LBB1_19:        ;cond_next48.loopexit3
LBB1_20:        ;cond_next48
        cmplwi cr0, r27, 0
        beq cr0, LBB1_22        ;UnifiedReturnBlock
...


This is CodeGen/PowerPC/branch-opt.ll


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@31006 91177308-0d34-0410-b5e6-96231b3b80d8
2006-10-17 18:16:40 +00:00
Chris Lattner
c50ffcb7fc Reenable this pass, fixing the bugs in it.
It now correctly deletes unreachable blocks and blocks that are empty.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@31000 91177308-0d34-0410-b5e6-96231b3b80d8
2006-10-17 17:13:52 +00:00
Chris Lattner
8f16eb98ed disable this pass for now, it's causing issues
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@30951 91177308-0d34-0410-b5e6-96231b3b80d8
2006-10-14 00:30:06 +00:00
Chris Lattner
7821a8afd3 falling off the end of a function is ok with an unreachable instruction.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@30950 91177308-0d34-0410-b5e6-96231b3b80d8
2006-10-14 00:21:48 +00:00
Chris Lattner
eb15eeec39 disable some objectionable code, maybe we can bring this pass to life
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@30939 91177308-0d34-0410-b5e6-96231b3b80d8
2006-10-13 20:43:10 +00:00
Misha Brukman
edf128a7fa Remove trailing whitespace
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@21420 91177308-0d34-0410-b5e6-96231b3b80d8
2005-04-21 22:36:52 +00:00
Reid Spencer
551ccae044 Changes For Bug 352
Move include/Config and include/Support into include/llvm/Config,
include/llvm/ADT and include/llvm/Support. From here on out, all LLVM
public header files must be under include/llvm/.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@16137 91177308-0d34-0410-b5e6-96231b3b80d8
2004-09-01 22:55:40 +00:00
Chris Lattner
4ae131e5da Dereferencing end() is bad.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@15402 91177308-0d34-0410-b5e6-96231b3b80d8
2004-08-01 09:51:42 +00:00
Alkis Evlogimenos
f978a1db51 Make OptimizeBlock take a MachineFunction::iterator instead of a
MachineBasicBlock* as a parameter so that nxext() and prior() helper
functions can work naturally on it.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@15376 91177308-0d34-0410-b5e6-96231b3b80d8
2004-07-31 19:24:41 +00:00
Chris Lattner
7f74340733 Next on a pointer increments the pointer, not an iterator
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@15375 91177308-0d34-0410-b5e6-96231b3b80d8
2004-07-31 18:40:36 +00:00
Alkis Evlogimenos
9fd332392c Use next() helper to make code more readable. Use
MachineFunction::iterator instead of MachineBasicBlock* to avoid
dereferencing end iterators.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@15373 91177308-0d34-0410-b5e6-96231b3b80d8
2004-07-31 15:14:29 +00:00
Alkis Evlogimenos
dd04583781 Use MachineFunction::iterator instead of a MachineBasicBlock* because
FallThrough maybe == to MF.end().


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@15372 91177308-0d34-0410-b5e6-96231b3b80d8
2004-07-31 15:03:52 +00:00
Chris Lattner
21ab22e475 Implement a simple target-independent CFG cleanup pass
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@15368 91177308-0d34-0410-b5e6-96231b3b80d8
2004-07-31 10:01:27 +00:00