[llvm-commits] [llvm] r143093 - in /llvm/trunk: lib/Transforms/Scalar/IndVarSimplify.cpp test/Transforms/IndVarSimplify/sink-alloca.ll
Eli Friedman
eli.friedman at gmail.com
Wed Oct 26 18:33:51 PDT 2011
Author: efriedma
Date: Wed Oct 26 20:33:51 2011
New Revision: 143093
URL: http://llvm.org/viewvc/llvm-project?rev=143093&view=rev
Log:
It is not safe to sink an alloca into a stacksave/stackrestore pair, so don't do that. <rdar://problem/10352360>
Modified:
llvm/trunk/lib/Transforms/Scalar/IndVarSimplify.cpp
llvm/trunk/test/Transforms/IndVarSimplify/sink-alloca.ll
Modified: llvm/trunk/lib/Transforms/Scalar/IndVarSimplify.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Transforms/Scalar/IndVarSimplify.cpp?rev=143093&r1=143092&r2=143093&view=diff
==============================================================================
--- llvm/trunk/lib/Transforms/Scalar/IndVarSimplify.cpp (original)
+++ llvm/trunk/lib/Transforms/Scalar/IndVarSimplify.cpp Wed Oct 26 20:33:51 2011
@@ -1680,11 +1680,12 @@
if (isa<LandingPadInst>(I))
continue;
- // Don't sink static AllocaInsts out of the entry block, which would
- // turn them into dynamic allocas!
- if (AllocaInst *AI = dyn_cast<AllocaInst>(I))
- if (AI->isStaticAlloca())
- continue;
+ // Don't sink alloca: we never want to sink static alloca's out of the
+ // entry block, and correctly sinking dynamic alloca's requires
+ // checks for stacksave/stackrestore intrinsics.
+ // FIXME: Refactor this check somehow?
+ if (isa<AllocaInst>(I))
+ continue;
// Determine if there is a use in or before the loop (direct or
// otherwise).
Modified: llvm/trunk/test/Transforms/IndVarSimplify/sink-alloca.ll
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/Transforms/IndVarSimplify/sink-alloca.ll?rev=143093&r1=143092&r2=143093&view=diff
==============================================================================
--- llvm/trunk/test/Transforms/IndVarSimplify/sink-alloca.ll (original)
+++ llvm/trunk/test/Transforms/IndVarSimplify/sink-alloca.ll Wed Oct 26 20:33:51 2011
@@ -1,15 +1,10 @@
; RUN: opt < %s -indvars -S | FileCheck %s
-; PR4775
-
-; Indvars shouldn't sink the alloca out of the entry block, even though
-; it's not used until after the loop.
-
target datalayout = "e-p:32:32:32-i1:8:8-i8:8:8-i16:16:16-i32:32:32-i64:32:64-f32:32:32-f64:32:64-v64:64:64-v128:128:128-a0:0:64-f80:128:128"
target triple = "i386-apple-darwin10.0"
- at llvm.used = appending global [1 x i8*] [i8* bitcast (i32 ()* @main to i8*)],
-section "llvm.metadata" ; <[1 x i8*]*> [#uses=0]
-
+; PR4775
+; Indvars shouldn't sink the alloca out of the entry block, even though
+; it's not used until after the loop.
define i32 @main() nounwind {
; CHECK: entry:
; CHECK-NEXT: %result.i = alloca i32, align 4
@@ -27,5 +22,35 @@
%tmp.i = volatile load i32* %result.i ; <i32> [#uses=0]
ret i32 0
}
-
declare i32 @bar()
+
+; <rdar://problem/10352360>
+; Indvars shouldn't sink the first alloca between the stacksave and stackrestore
+; intrinsics.
+declare i8* @a(...)
+declare i8* @llvm.stacksave() nounwind
+declare void @llvm.stackrestore(i8*) nounwind
+define void @h(i64 %n) nounwind uwtable ssp {
+; CHECK: entry:
+; CHECK-NEXT: %vla = alloca i8*
+; CHECK-NEXT: %savedstack = call i8* @llvm.stacksave()
+entry:
+ %vla = alloca i8*, i64 %n, align 16
+ %savedstack = call i8* @llvm.stacksave() nounwind
+ %vla.i = alloca i8*, i64 %n, align 16
+ br label %for.body.i
+
+for.body.i:
+ %indvars.iv37.i = phi i64 [ %indvars.iv.next38.i, %for.body.i ], [ 0, %entry ]
+ %call.i = call i8* (...)* @a() nounwind
+ %arrayidx.i = getelementptr inbounds i8** %vla.i, i64 %indvars.iv37.i
+ store i8* %call.i, i8** %arrayidx.i, align 8
+ %indvars.iv.next38.i = add i64 %indvars.iv37.i, 1
+ %exitcond5 = icmp eq i64 %indvars.iv.next38.i, %n
+ br i1 %exitcond5, label %g.exit, label %for.body.i
+
+g.exit:
+ call void @llvm.stackrestore(i8* %savedstack) nounwind
+ %call1 = call i8* (...)* @a(i8** %vla) nounwind
+ ret void
+}
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