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b40f14eb89
In signed arithmetic we could end up with an i64 trip count for an i32 phi. Because it is signed arithmetic we know that this is only defined if the i32 does not wrap. It is therefore safe to truncate the i64 trip count to a i32 value. Fixes PR18049. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@195787 91177308-0d34-0410-b5e6-96231b3b80d8
40 lines
1.1 KiB
LLVM
40 lines
1.1 KiB
LLVM
; RUN: opt -S -loop-vectorize -force-vector-width=2 -force-vector-unroll=1 -mcpu=prescott < %s | FileCheck %s
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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-f80:32:32-n8:16:32-S128"
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target triple = "i386-unknown-freebsd11.0"
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@big = external global [0 x i32]
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; PR18049
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; We need to truncate the exit count to i32. This is legal because the
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; arithmetic is signed (%inc is nsw).
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; CHECK-LABEL: tripcount
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; CHECK: trunc i64 %count to i32
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define void @tripcount(i64 %count) {
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entry:
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%cmp6 = icmp sgt i64 %count, 0
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br i1 %cmp6, label %for.body.preheader, label %for.end
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for.body.preheader:
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br label %for.body
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for.body:
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%i.07 = phi i32 [ %inc, %for.body ], [ 0, %for.body.preheader ]
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%arrayidx = getelementptr inbounds [0 x i32]* @big, i32 0, i32 %i.07
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%0 = load i32* %arrayidx, align 4
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%neg = xor i32 %0, -1
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store i32 %neg, i32* %arrayidx, align 4
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%inc = add nsw i32 %i.07, 1
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%conv = sext i32 %inc to i64
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%cmp = icmp slt i64 %conv, %count
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br i1 %cmp, label %for.body, label %for.end.loopexit
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for.end.loopexit:
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br label %for.end
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for.end:
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ret void
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}
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