OptimizeCompareInstr should avoid iterating pass the beginning of the MBB when the 'and' instruction is after the comparison.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@114506 91177308-0d34-0410-b5e6-96231b3b80d8
This commit is contained in:
Evan Cheng 2010-09-21 23:49:07 +00:00
parent 882ef2b76a
commit 691e64a54c
2 changed files with 90 additions and 1 deletions

View File

@ -1455,7 +1455,8 @@ OptimizeCompareInstr(MachineInstr *CmpInstr, unsigned SrcReg, int CmpMask,
// Check that CPSR isn't set between the comparison instruction and the one we
// want to change.
MachineBasicBlock::const_iterator I = CmpInstr, E = MI;
MachineBasicBlock::const_iterator I = CmpInstr, E = MI,
B = MI->getParent()->begin();
--I;
for (; I != E; --I) {
const MachineInstr &Instr = *I;
@ -1469,6 +1470,10 @@ OptimizeCompareInstr(MachineInstr *CmpInstr, unsigned SrcReg, int CmpMask,
if (MO.getReg() == ARM::CPSR)
return false;
}
if (I == B)
// The 'and' is below the comparison instruction.
return false;
}
// Set the "zero" bit in CPSR.

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@ -0,0 +1,84 @@
; RUN: llc < %s -mtriple=thumbv7-apple-darwin10
declare noalias i8* @malloc(i32) nounwind
define internal void @gl_DrawPixels(i32 %width, i32 %height, i32 %format, i32 %type, i8* %pixels) nounwind {
entry:
br i1 undef, label %bb3.i, label %bb3
bb3.i: ; preds = %entry
unreachable
gl_error.exit: ; preds = %bb22
ret void
bb3: ; preds = %entry
br i1 false, label %bb5, label %bb4
bb4: ; preds = %bb3
br label %bb5
bb5: ; preds = %bb4, %bb3
br i1 undef, label %bb19, label %bb22
bb19: ; preds = %bb5
switch i32 %type, label %bb3.i6.i [
i32 5120, label %bb1.i13
i32 5121, label %bb1.i13
i32 6656, label %bb9.i.i6
]
bb9.i.i6: ; preds = %bb19
br label %bb1.i13
bb3.i6.i: ; preds = %bb19
unreachable
bb1.i13: ; preds = %bb9.i.i6, %bb19, %bb19
br i1 undef, label %bb3.i17, label %bb2.i16
bb2.i16: ; preds = %bb1.i13
unreachable
bb3.i17: ; preds = %bb1.i13
br i1 undef, label %bb4.i18, label %bb23.i
bb4.i18: ; preds = %bb3.i17
%0 = mul nsw i32 %height, %width
%1 = and i32 %0, 7
%not..i = icmp ne i32 %1, 0
%2 = zext i1 %not..i to i32
%storemerge2.i = add i32 0, %2
%3 = call noalias i8* @malloc(i32 %storemerge2.i) nounwind
br i1 undef, label %bb3.i9, label %bb9.i
bb9.i: ; preds = %bb4.i18
br i1 undef, label %bb13.i19, label %bb.i24.i
bb13.i19: ; preds = %bb9.i
br i1 undef, label %bb14.i20, label %bb15.i
bb14.i20: ; preds = %bb13.i19
unreachable
bb15.i: ; preds = %bb13.i19
unreachable
bb.i24.i: ; preds = %bb.i24.i, %bb9.i
%storemerge1.i21.i = phi i32 [ %4, %bb.i24.i ], [ 0, %bb9.i ]
%4 = add i32 %storemerge1.i21.i, 1
%exitcond47.i = icmp eq i32 %4, %storemerge2.i
br i1 %exitcond47.i, label %bb22, label %bb.i24.i
bb23.i: ; preds = %bb3.i17
unreachable
bb3.i9: ; preds = %bb4.i18
unreachable
bb22: ; preds = %bb.i24.i, %bb5
br i1 undef, label %gl_error.exit, label %bb23
bb23: ; preds = %bb22
ret void
}