[llvm-commits] [llvm] r151002 - in /llvm/trunk: lib/CodeGen/MachineCopyPropagation.cpp lib/CodeGen/Passes.cpp test/CodeGen/X86/2012-02-20-MachineCPBug.ll test/CodeGen/X86/machine-cp.ll
Evan Cheng
evan.cheng at apple.com
Mon Feb 20 15:28:17 PST 2012
Author: evancheng
Date: Mon Feb 20 17:28:17 2012
New Revision: 151002
URL: http://llvm.org/viewvc/llvm-project?rev=151002&view=rev
Log:
Fix machine-cp by having it to check sub-register indicies. e.g.
ecx = mov eax
al = mov ch
The second copy is not a nop because the sub-indices of ecx,ch is not the
same of that of eax/al.
Re-enabled machine-cp.
PR11940
Added:
llvm/trunk/test/CodeGen/X86/2012-02-20-MachineCPBug.ll
Modified:
llvm/trunk/lib/CodeGen/MachineCopyPropagation.cpp
llvm/trunk/lib/CodeGen/Passes.cpp
llvm/trunk/test/CodeGen/X86/machine-cp.ll
Modified: llvm/trunk/lib/CodeGen/MachineCopyPropagation.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/CodeGen/MachineCopyPropagation.cpp?rev=151002&r1=151001&r2=151002&view=diff
==============================================================================
--- llvm/trunk/lib/CodeGen/MachineCopyPropagation.cpp (original)
+++ llvm/trunk/lib/CodeGen/MachineCopyPropagation.cpp Mon Feb 20 17:28:17 2012
@@ -99,6 +99,31 @@
return true;
}
+/// isNopCopy - Return true if the specified copy is really a nop. That is
+/// if the source of the copy is the same of the definition of the copy that
+/// supplied the source. If the source of the copy is a sub-register than it
+/// must check the sub-indices match. e.g.
+/// ecx = mov eax
+/// al = mov cl
+/// But not
+/// ecx = mov eax
+/// al = mov ch
+static bool isNopCopy(MachineInstr *CopyMI, unsigned Def, unsigned Src,
+ const TargetRegisterInfo *TRI) {
+ unsigned SrcSrc = CopyMI->getOperand(1).getReg();
+ if (Def == SrcSrc)
+ return true;
+ if (TRI->isSubRegister(SrcSrc, Def)) {
+ unsigned SrcDef = CopyMI->getOperand(0).getReg();
+ unsigned SubIdx = TRI->getSubRegIndex(SrcSrc, Def);
+ if (!SubIdx)
+ return false;
+ return SubIdx == TRI->getSubRegIndex(SrcDef, Src);
+ }
+
+ return false;
+}
+
bool MachineCopyPropagation::CopyPropagateBlock(MachineBasicBlock &MBB) {
SmallSetVector<MachineInstr*, 8> MaybeDeadCopies; // Candidates for deletion
DenseMap<unsigned, MachineInstr*> AvailCopyMap; // Def -> available copies map
@@ -122,10 +147,9 @@
DenseMap<unsigned, MachineInstr*>::iterator CI = AvailCopyMap.find(Src);
if (CI != AvailCopyMap.end()) {
MachineInstr *CopyMI = CI->second;
- unsigned SrcSrc = CopyMI->getOperand(1).getReg();
if (!ReservedRegs.test(Def) &&
(!ReservedRegs.test(Src) || NoInterveningSideEffect(CopyMI, MI)) &&
- (SrcSrc == Def || TRI->isSubRegister(SrcSrc, Def))) {
+ isNopCopy(CopyMI, Def, Src, TRI)) {
// The two copies cancel out and the source of the first copy
// hasn't been overridden, eliminate the second one. e.g.
// %ECX<def> = COPY %EAX<kill>
Modified: llvm/trunk/lib/CodeGen/Passes.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/CodeGen/Passes.cpp?rev=151002&r1=151001&r2=151002&view=diff
==============================================================================
--- llvm/trunk/lib/CodeGen/Passes.cpp (original)
+++ llvm/trunk/lib/CodeGen/Passes.cpp Mon Feb 20 17:28:17 2012
@@ -69,7 +69,7 @@
static cl::opt<bool> DisableCGP("disable-cgp", cl::Hidden,
cl::desc("Disable Codegen Prepare"));
static cl::opt<bool> DisableCopyProp("disable-copyprop", cl::Hidden,
- cl::desc("Disable Copy Propagation pass"), cl::init(true)); // PR11940
+ cl::desc("Disable Copy Propagation pass"));
static cl::opt<bool> PrintLSR("print-lsr-output", cl::Hidden,
cl::desc("Print LLVM IR produced by the loop-reduce pass"));
static cl::opt<bool> PrintISelInput("print-isel-input", cl::Hidden,
Added: llvm/trunk/test/CodeGen/X86/2012-02-20-MachineCPBug.ll
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/CodeGen/X86/2012-02-20-MachineCPBug.ll?rev=151002&view=auto
==============================================================================
--- llvm/trunk/test/CodeGen/X86/2012-02-20-MachineCPBug.ll (added)
+++ llvm/trunk/test/CodeGen/X86/2012-02-20-MachineCPBug.ll Mon Feb 20 17:28:17 2012
@@ -0,0 +1,77 @@
+; RUN: llc < %s -mtriple=i386-apple-macosx | FileCheck %s
+; PR11940: Do not optimize away movb %al, %ch
+
+%struct.APInt = type { i64* }
+
+declare noalias i8* @calloc(i32, i32) nounwind
+
+define void @bug(%struct.APInt* noalias nocapture sret %agg.result, %struct.APInt* nocapture %this, i32 %rotateAmt) nounwind align 2 {
+entry:
+; CHECK: bug:
+ %call = tail call i8* @calloc(i32 1, i32 32)
+ %call.i = tail call i8* @calloc(i32 1, i32 32) nounwind
+ %0 = bitcast i8* %call.i to i64*
+ %rem.i = and i32 %rotateAmt, 63
+ %div.i = lshr i32 %rotateAmt, 6
+ %cmp.i = icmp eq i32 %rem.i, 0
+ br i1 %cmp.i, label %for.cond.preheader.i, label %if.end.i
+
+for.cond.preheader.i: ; preds = %entry
+ %sub.i = sub i32 4, %div.i
+ %cmp23.i = icmp eq i32 %div.i, 4
+ br i1 %cmp23.i, label %for.body9.lr.ph.i, label %for.body.lr.ph.i
+
+for.body.lr.ph.i: ; preds = %for.cond.preheader.i
+ %pVal.i = getelementptr inbounds %struct.APInt* %this, i32 0, i32 0
+ %.pre5.i = load i64** %pVal.i, align 4
+ br label %for.body.i
+
+for.body.i: ; preds = %for.body.i, %for.body.lr.ph.i
+ %i.04.i = phi i32 [ 0, %for.body.lr.ph.i ], [ %inc.i, %for.body.i ]
+ %add.i = add i32 %i.04.i, %div.i
+ %arrayidx.i = getelementptr inbounds i64* %.pre5.i, i32 %add.i
+ %1 = load i64* %arrayidx.i, align 4
+ %arrayidx3.i = getelementptr inbounds i64* %0, i32 %i.04.i
+ store i64 %1, i64* %arrayidx3.i, align 4
+ %inc.i = add i32 %i.04.i, 1
+ %cmp2.i = icmp ult i32 %inc.i, %sub.i
+ br i1 %cmp2.i, label %for.body.i, label %if.end.i
+
+if.end.i: ; preds = %for.body.i, %entry
+ %cmp81.i = icmp eq i32 %div.i, 3
+ br i1 %cmp81.i, label %_ZNK5APInt4lshrEj.exit, label %for.body9.lr.ph.i
+
+for.body9.lr.ph.i: ; preds = %if.end.i, %for.cond.preheader.i
+ %sub58.i = sub i32 3, %div.i
+ %pVal11.i = getelementptr inbounds %struct.APInt* %this, i32 0, i32 0
+ %sh_prom.i = zext i32 %rem.i to i64
+ %sub17.i = sub i32 64, %rem.i
+ %sh_prom18.i = zext i32 %sub17.i to i64
+ %.pre.i = load i64** %pVal11.i, align 4
+ br label %for.body9.i
+
+for.body9.i: ; preds = %for.body9.i, %for.body9.lr.ph.i
+; CHECK: %for.body9.i
+; CHECK: movb %al, %ch
+ %i6.02.i = phi i32 [ 0, %for.body9.lr.ph.i ], [ %inc21.i, %for.body9.i ]
+ %add10.i = add i32 %i6.02.i, %div.i
+ %arrayidx12.i = getelementptr inbounds i64* %.pre.i, i32 %add10.i
+ %2 = load i64* %arrayidx12.i, align 4
+ %shr.i = lshr i64 %2, %sh_prom.i
+ %add14.i = add i32 %add10.i, 1
+ %arrayidx16.i = getelementptr inbounds i64* %.pre.i, i32 %add14.i
+ %3 = load i64* %arrayidx16.i, align 4
+ %shl.i = shl i64 %3, %sh_prom18.i
+ %or.i = or i64 %shl.i, %shr.i
+ %arrayidx19.i = getelementptr inbounds i64* %0, i32 %i6.02.i
+ store i64 %or.i, i64* %arrayidx19.i, align 4
+ %inc21.i = add i32 %i6.02.i, 1
+ %cmp8.i = icmp ult i32 %inc21.i, %sub58.i
+ br i1 %cmp8.i, label %for.body9.i, label %_ZNK5APInt4lshrEj.exit
+
+_ZNK5APInt4lshrEj.exit: ; preds = %for.body9.i, %if.end.i
+ %call.i1 = tail call i8* @calloc(i32 1, i32 32) nounwind
+ %4 = getelementptr inbounds %struct.APInt* %agg.result, i32 0, i32 0
+ store i64* %0, i64** %4, align 4
+ ret void
+}
Modified: llvm/trunk/test/CodeGen/X86/machine-cp.ll
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/CodeGen/X86/machine-cp.ll?rev=151002&r1=151001&r2=151002&view=diff
==============================================================================
--- llvm/trunk/test/CodeGen/X86/machine-cp.ll (original)
+++ llvm/trunk/test/CodeGen/X86/machine-cp.ll Mon Feb 20 17:28:17 2012
@@ -1,4 +1,4 @@
-; RUN: llc -mtriple=x86_64-apple-macosx -mcpu=nocona < %s -disable-copyprop=false | FileCheck %s
+; RUN: llc -mtriple=x86_64-apple-macosx -mcpu=nocona < %s | FileCheck %s
; After tail duplication, two copies in an early exit BB can be cancelled out.
; rdar://10640363
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