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Summary: If the src, dst and size of a memcpy are known to be 4 byte aligned we can call __memcpy_4() instead of memcpy(). Reviewers: robertlytton Reviewed By: robertlytton CC: llvm-commits Differential Revision: http://llvm-reviews.chandlerc.com/D2871 git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@202395 91177308-0d34-0410-b5e6-96231b3b80d8
33 lines
956 B
LLVM
33 lines
956 B
LLVM
; RUN: llc < %s -march=xcore | FileCheck %s
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; Optimize memcpy to __memcpy_4 if src, dst and size are all 4 byte aligned.
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define void @f1(i8* %dst, i8* %src, i32 %n) nounwind {
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; CHECK-LABEL: f1:
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; CHECK: bl __memcpy_4
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entry:
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%0 = shl i32 %n, 2
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call void @llvm.memcpy.p0i8.p0i8.i32(i8* %dst, i8* %src, i32 %0, i32 4, i1 false)
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ret void
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}
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; Can't optimize - size is not a multiple of 4.
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define void @f2(i8* %dst, i8* %src, i32 %n) nounwind {
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; CHECK-LABEL: f2:
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; CHECK: bl memcpy
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entry:
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call void @llvm.memcpy.p0i8.p0i8.i32(i8* %dst, i8* %src, i32 %n, i32 4, i1 false)
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ret void
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}
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; Can't optimize - alignment is not a multiple of 4.
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define void @f3(i8* %dst, i8* %src, i32 %n) nounwind {
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; CHECK-LABEL: f3:
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; CHECK: bl memcpy
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entry:
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%0 = shl i32 %n, 2
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call void @llvm.memcpy.p0i8.p0i8.i32(i8* %dst, i8* %src, i32 %0, i32 2, i1 false)
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ret void
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}
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declare void @llvm.memcpy.p0i8.p0i8.i32(i8* nocapture, i8* nocapture, i32, i32, i1) nounwind
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