diff --git a/llvm/lib/CodeGen/BranchFolding.cpp b/llvm/lib/CodeGen/BranchFolding.cpp index 1ab3df28572b..1ce83f81af4c 100644 --- a/llvm/lib/CodeGen/BranchFolding.cpp +++ b/llvm/lib/CodeGen/BranchFolding.cpp @@ -700,6 +700,7 @@ bool BranchFolder::TailMergeBlocks(MachineFunction &MF) { for (MachineFunction::iterator I = MF.begin(), E = MF.end(); I != E; ++I) { if (I->pred_size() >= 2 && I->pred_size() < TailMergeThreshold) { + SmallPtrSet UniquePreds; MachineBasicBlock *IBB = I; MachineBasicBlock *PredBB = prior(I); MergePotentials.clear(); @@ -710,6 +711,9 @@ bool BranchFolder::TailMergeBlocks(MachineFunction &MF) { // Skip blocks that loop to themselves, can't tail merge these. if (PBB==IBB) continue; + // Visit each predecessor only once. + if (!UniquePreds.insert(PBB)) + continue; MachineBasicBlock *TBB = 0, *FBB = 0; SmallVector Cond; if (!TII->AnalyzeBranch(*PBB, TBB, FBB, Cond, true)) { @@ -850,27 +854,6 @@ bool BranchFolder::CanFallThrough(MachineBasicBlock *CurBB) { return CanFallThrough(CurBB, CurUnAnalyzable, TBB, FBB, Cond); } -/// RemoveDuplicateSuccessor - make sure block Pred has at most one -/// successor edge leading to Succ. This is only called in one place, -/// but Chris prefers that it be a separate function. -static void RemoveDuplicateSuccessor(MachineBasicBlock *Pred, - MachineBasicBlock *Succ) { - MachineBasicBlock::succ_iterator SI = Pred->succ_begin(); - bool found = false; - while (SI != Pred->succ_end()) { - if (*SI == Succ) { - if (!found) { - found = true; - ++SI; - } else { - SI = Pred->removeSuccessor(SI); - } - } else { - ++SI; - } - } -} - /// IsBetterFallthrough - Return true if it would be clearly better to /// fall-through to MBB1 than to fall through into MBB2. This has to return /// a strict ordering, returning true for both (MBB1,MBB2) and (MBB2,MBB1) will @@ -914,10 +897,6 @@ void BranchFolder::OptimizeBlock(MachineBasicBlock *MBB) { while (!MBB->pred_empty()) { MachineBasicBlock *Pred = *(MBB->pred_end()-1); Pred->ReplaceUsesOfBlockWith(MBB, FallThrough); - // If this resulted in a predecessor with true and false edges - // both going to the fallthrough block, clean up; - // BranchFolding doesn't like this. - RemoveDuplicateSuccessor(Pred, FallThrough); } // If MBB was the target of a jump table, update jump tables to go to the // fallthrough instead. diff --git a/llvm/test/CodeGen/Thumb2/thumb2-ifcvt2.ll b/llvm/test/CodeGen/Thumb2/thumb2-ifcvt2.ll index 15ccb2d18502..299ab4d642df 100644 --- a/llvm/test/CodeGen/Thumb2/thumb2-ifcvt2.ll +++ b/llvm/test/CodeGen/Thumb2/thumb2-ifcvt2.ll @@ -82,7 +82,7 @@ define fastcc void @t2() nounwind { entry: ; CHECK: t2: ; CHECK: cmp r0, #0 -; CHECK: bne.n +; CHECK: beq.n br i1 undef, label %bb.i.i3, label %growMapping.exit bb.i.i3: ; preds = %entry diff --git a/llvm/test/CodeGen/X86/2009-08-06-branchfolder-crash.ll b/llvm/test/CodeGen/X86/2009-08-06-branchfolder-crash.ll index 5e58725cb99a..2c8cf0c8cd56 100644 --- a/llvm/test/CodeGen/X86/2009-08-06-branchfolder-crash.ll +++ b/llvm/test/CodeGen/X86/2009-08-06-branchfolder-crash.ll @@ -88,3 +88,55 @@ for.inc: ; preds = %for.inc, %lor.end.i, %lor.rhs.i, %land.lhs.true3.i } declare i32 @safe() + +define i32 @func_35(i8 signext %p_35) nounwind readonly { +entry: + %tobool = icmp eq i8 %p_35, 0 ; [#uses=1] + br i1 %tobool, label %lor.lhs.false, label %if.then + +lor.lhs.false: ; preds = %entry + %tmp1 = load i8* @g_3 ; [#uses=1] + %tobool3 = icmp eq i8 %tmp1, 0 ; [#uses=1] + br i1 %tobool3, label %return, label %if.then + +if.then: ; preds = %lor.lhs.false, %entry + %tmp4 = load i8* @g_3 ; [#uses=1] + %conv5 = sext i8 %tmp4 to i32 ; [#uses=1] + ret i32 %conv5 + +return: ; preds = %lor.lhs.false + ret i32 0 +} + +define void @bar(i32 %p_5) noreturn nounwind { +entry: + %cmp = icmp sgt i32 %p_5, 0 ; [#uses=2] + %call = tail call i32 @safe() nounwind ; [#uses=1] + %conv1 = trunc i32 %call to i8 ; [#uses=3] + %tobool.i = xor i1 %cmp, true ; [#uses=3] + %cmp.i = icmp sgt i8 %conv1, 0 ; [#uses=3] + %or.cond.i = or i1 %cmp.i, %tobool.i ; [#uses=1] + br i1 %or.cond.i, label %lor.rhs.i, label %land.lhs.true3.i + +land.lhs.true3.i: ; preds = %entry + %xor = zext i1 %cmp to i32 ; [#uses=1] + %conv5.i = sext i8 %conv1 to i32 ; [#uses=1] + %cmp7.i = icmp slt i32 %conv5.i, %xor ; [#uses=1] + %cmp7.i.not = xor i1 %cmp7.i, true ; [#uses=1] + %or.cond23.i = and i1 %cmp.i, %tobool.i ; [#uses=1] + %or.cond = and i1 %cmp7.i.not, %or.cond23.i ; [#uses=1] + br i1 %or.cond, label %lor.end.i, label %for.inc + +lor.rhs.i: ; preds = %entry + %or.cond23.i.old = and i1 %cmp.i, %tobool.i ; [#uses=1] + br i1 %or.cond23.i.old, label %lor.end.i, label %for.inc + +lor.end.i: ; preds = %lor.rhs.i, %land.lhs.true3.i + %tobool19.i = icmp eq i8 %conv1, 0 ; [#uses=0] + br label %for.inc + +for.inc: ; preds = %for.inc, %lor.end.i, %lor.rhs.i, %land.lhs.true3.i + br label %for.inc +} + +declare i32 @safe() diff --git a/llvm/test/CodeGen/X86/omit-label.ll b/llvm/test/CodeGen/X86/omit-label.ll index 457b66b35dca..6450f95d9b9e 100644 --- a/llvm/test/CodeGen/X86/omit-label.ll +++ b/llvm/test/CodeGen/X86/omit-label.ll @@ -1,7 +1,11 @@ -; RUN: llvm-as < %s | llc -march=x86-64 | grep BB1_1: +; RUN: llvm-as < %s | llc -march=x86-64 -asm-verbose=false | FileCheck %s ; PR4126 +; PR4732 -; Don't omit this label's definition. +; Don't omit these labels' definitions. + +; CHECK: bux: +; CHECK: .LBB1_1: define void @bux(i32 %p_53) nounwind optsize { entry: @@ -21,3 +25,33 @@ bb3: ; preds = %bb.i, %entry } declare i32 @baz(...) + +; Don't omit this label in the assembly output. +; CHECK: int321: +; CHECK: jne .LBB2_1 +; CHECK: jle .LBB2_1 +; CHECK: .LBB2_1: + +define void @int321(i8 signext %p_103, i32 %uint8p_104) nounwind readnone { +entry: + %tobool = icmp eq i8 %p_103, 0 ; [#uses=1] + %cmp.i = icmp sgt i8 %p_103, 0 ; [#uses=1] + %or.cond = and i1 %tobool, %cmp.i ; [#uses=1] + br i1 %or.cond, label %land.end.i, label %for.cond.preheader + +land.end.i: ; preds = %entry + %conv3.i = sext i8 %p_103 to i32 ; [#uses=1] + %div.i = sdiv i32 1, %conv3.i ; [#uses=1] + %tobool.i = icmp eq i32 %div.i, -2147483647 ; [#uses=0] + br label %for.cond.preheader + +for.cond.preheader: ; preds = %land.end.i, %entry + %cmp = icmp sgt i8 %p_103, 1 ; [#uses=1] + br i1 %cmp, label %for.end.split, label %for.cond + +for.cond: ; preds = %for.cond.preheader, %for.cond + br label %for.cond + +for.end.split: ; preds = %for.cond.preheader + ret void +}