Special-case static allocas in IndVarSimplify's loop invariant
sinking code, since they are special. If the loop preheader happens to be the entry block of a function, don't sink static allocas out of it. This fixes PR4775. llvm-svn: 80010
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@ -553,6 +553,11 @@ void IndVarSimplify::SinkUnusedInvariants(Loop *L) {
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// dominates the exit block.
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// dominates the exit block.
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if (I->mayHaveSideEffects() || I->mayReadFromMemory())
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if (I->mayHaveSideEffects() || I->mayReadFromMemory())
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continue;
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continue;
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// Don't sink static AllocaInsts out of the entry block, which would
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// turn them into dynamic allocas!
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if (AllocaInst *AI = dyn_cast<AllocaInst>(I))
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if (AI->isStaticAlloca())
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continue;
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// Determine if there is a use in or before the loop (direct or
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// Determine if there is a use in or before the loop (direct or
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// otherwise).
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// otherwise).
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bool UsedInLoop = false;
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bool UsedInLoop = false;
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@ -0,0 +1,31 @@
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; RUN: llvm-as < %s | opt -indvars | llvm-dis | FileCheck %s
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; PR4775
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; Indvars shouldn't sink the alloca out of the entry block, even though
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; it's not used until after the loop.
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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"
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target triple = "i386-apple-darwin10.0"
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@llvm.used = appending global [1 x i8*] [i8* bitcast (i32 ()* @main to i8*)],
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section "llvm.metadata" ; <[1 x i8*]*> [#uses=0]
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define i32 @main() nounwind {
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; CHECK: entry:
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; CHECK-NEXT: %result.i = alloca i32, align 4
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entry:
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%result.i = alloca i32, align 4 ; <i32*> [#uses=2]
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br label %while.cond
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while.cond: ; preds = %while.cond, %entry
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%call = call i32 @bar() nounwind ; <i32> [#uses=1]
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%tobool = icmp eq i32 %call, 0 ; <i1> [#uses=1]
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br i1 %tobool, label %while.end, label %while.cond
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while.end: ; preds = %while.cond
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volatile store i32 0, i32* %result.i
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%tmp.i = volatile load i32* %result.i ; <i32> [#uses=0]
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ret i32 0
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}
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declare i32 @bar()
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