diff options
| -rw-r--r-- | llvm/lib/CodeGen/StackColoring.cpp | 4 | ||||
| -rw-r--r-- | llvm/test/CodeGen/X86/StackColoring.ll | 56 |
2 files changed, 55 insertions, 5 deletions
diff --git a/llvm/lib/CodeGen/StackColoring.cpp b/llvm/lib/CodeGen/StackColoring.cpp index dfaad585ca4..281836e909d 100644 --- a/llvm/lib/CodeGen/StackColoring.cpp +++ b/llvm/lib/CodeGen/StackColoring.cpp @@ -75,10 +75,10 @@ ProtectFromEscapedAllocas("protect-from-escaped-allocas", /// Enable enhanced dataflow scheme for lifetime analysis (treat first /// use of stack slot as start of slot lifetime, as opposed to looking /// for LIFETIME_START marker). See "Implementation notes" below for -/// more info. +/// more info. FIXME: set to false for the moment due to PR27903. static cl::opt<bool> LifetimeStartOnFirstUse("stackcoloring-lifetime-start-on-first-use", - cl::init(true), cl::Hidden, + cl::init(false), cl::Hidden, cl::desc("Treat stack lifetimes as starting on first use, not on START marker.")); diff --git a/llvm/test/CodeGen/X86/StackColoring.ll b/llvm/test/CodeGen/X86/StackColoring.ll index 153da98b26d..1c4ba8fe831 100644 --- a/llvm/test/CodeGen/X86/StackColoring.ll +++ b/llvm/test/CodeGen/X86/StackColoring.ll @@ -1,3 +1,4 @@ +; RUN: llc -mcpu=corei7 -no-stack-coloring=false -stackcoloring-lifetime-start-on-first-use=true < %s | FileCheck %s --check-prefix=FIRSTUSE --check-prefix=CHECK ; RUN: llc -mcpu=corei7 -no-stack-coloring=false < %s | FileCheck %s --check-prefix=YESCOLOR --check-prefix=CHECK ; RUN: llc -mcpu=corei7 -no-stack-coloring=true < %s | FileCheck %s --check-prefix=NOCOLOR --check-prefix=CHECK @@ -87,7 +88,8 @@ bb3: } ;CHECK-LABEL: myCall_w4: -;YESCOLOR: subq $120, %rsp +;FIRSTUSE: subq $120, %rsp +;YESCOLOR: subq $200, %rsp ;NOCOLOR: subq $408, %rsp define i32 @myCall_w4(i32 %in) { @@ -431,7 +433,8 @@ define i32 @shady_range(i32 %argc, i8** nocapture %argv) uwtable { ; start. See llvm bug 25776. ;CHECK-LABEL: ifthen_twoslots: -;YESCOLOR: subq $536, %rsp +;FIRSTUSE: subq $536, %rsp +;YESCOLOR: subq $1048, %rsp ;NOCOLOR: subq $1048, %rsp define i32 @ifthen_twoslots(i32 %x) #0 { @@ -486,7 +489,8 @@ cleanup: ; preds = %if.else, %if.then ; markers only. ;CHECK-LABEL: while_loop: -;YESCOLOR: subq $1032, %rsp +;FIRSTUSE: subq $1032, %rsp +;YESCOLOR: subq $1544, %rsp ;NOCOLOR: subq $1544, %rsp define i32 @while_loop(i32 %x) #0 { @@ -537,6 +541,52 @@ if.end: ; preds = %if.end.loopexit, %i ret i32 0 } +; Test case motivated by PR27903. Same routine inlined multiple times +; into a caller results in a multi-segment lifetime, but the second +; lifetime has no explicit references to the stack slot. +; +; FIXME: the "FIRSTUSE" stack size (56) below represents buggy/incorrect +; behavior not currently exposed on trunk, due to the fact that +; the "stackcoloring-lifetime-start-on-first-use" now defaults to +; false. When a better fix for PR27903 is checked in, this result +; will change to 96. + +;CHECK-LABEL: twobod_b27903: +;FIRSTUSE: subq $56, %rsp +;YESCOLOR: subq $96, %rsp +;NOCOLOR: subq $96, %rsp + +define i32 @twobod_b27903(i32 %y, i32 %x) { +entry: + %buffer.i = alloca [12 x i32], align 16 + %abc = alloca [12 x i32], align 16 + %tmp = bitcast [12 x i32]* %buffer.i to i8* + call void @llvm.lifetime.start(i64 48, i8* %tmp) + %idxprom.i = sext i32 %y to i64 + %arrayidx.i = getelementptr inbounds [12 x i32], [12 x i32]* %buffer.i, i64 0, i64 %idxprom.i + call void @inita(i32* %arrayidx.i) + %add.i = add nsw i32 %x, %y + call void @llvm.lifetime.end(i64 48, i8* %tmp) + %tobool = icmp eq i32 %y, 0 + br i1 %tobool, label %if.end, label %if.then + +if.then: ; preds = %entry + %tmp1 = bitcast [12 x i32]* %abc to i8* + call void @llvm.lifetime.start(i64 48, i8* %tmp1) + %arrayidx = getelementptr inbounds [12 x i32], [12 x i32]* %abc, i64 0, i64 %idxprom.i + call void @inita(i32* %arrayidx) + call void @llvm.lifetime.start(i64 48, i8* %tmp) + call void @inita(i32* %arrayidx.i) + %add.i9 = add nsw i32 %add.i, %y + call void @llvm.lifetime.end(i64 48, i8* %tmp) + call void @llvm.lifetime.end(i64 48, i8* %tmp1) + br label %if.end + +if.end: ; preds = %if.then, %entry + %x.addr.0 = phi i32 [ %add.i9, %if.then ], [ %add.i, %entry ] + ret i32 %x.addr.0 +} + declare void @inita(i32*) #2 declare void @bar([100 x i32]* , [100 x i32]*) nounwind |
