llvm/test/Transforms/SROA/slice-order-independence.ll
Duncan P. N. Exon Smith 0dee67560f SROA: Only split loads on byte boundaries
r199771 accidently broke the logic that makes sure that SROA only splits
load on byte boundaries.  If such a split happens, some bits get lost
when reassembling loads of wider types, causing data corruption.

Move the width check up to reject such splits early, avoiding the
corruption.  Fixes PR19250.

Patch by: Björn Steinbrink <bsteinbr@gmail.com>

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@211082 91177308-0d34-0410-b5e6-96231b3b80d8
2014-06-17 00:19:35 +00:00

38 lines
1.4 KiB
LLVM

; RUN: opt < %s -sroa -S | FileCheck %s
target datalayout = "e-p:64:64:64-p1:16:16:16-i1:8:8-i8:8:8-i16:16:16-i32:32:32-i64:32:64-f32:32:32-f64:64:64-v64:64:64-v128:128:128-a0:0:64-n8:16:32:64"
declare void @llvm.memcpy.p0i8.p0i8.i32(i8* nocapture, i8* nocapture, i32, i32, i1) nounwind
; Check that the chosen type for a split is independent from the order of
; slices even in case of types that are skipped because their width is not a
; byte width multiple
define void @skipped_inttype_first({ i16*, i32 }*) {
; CHECK-LABEL: @skipped_inttype_first
; CHECK: alloca i8*
%arg = alloca { i16*, i32 }, align 8
%2 = bitcast { i16*, i32 }* %0 to i8*
%3 = bitcast { i16*, i32 }* %arg to i8*
call void @llvm.memcpy.p0i8.p0i8.i32(i8* %3, i8* %2, i32 16, i32 8, i1 false)
%b = getelementptr inbounds { i16*, i32 }* %arg, i64 0, i32 0
%pb0 = bitcast i16** %b to i63*
%b0 = load i63* %pb0
%pb1 = bitcast i16** %b to i8**
%b1 = load i8** %pb1
ret void
}
define void @skipped_inttype_last({ i16*, i32 }*) {
; CHECK-LABEL: @skipped_inttype_last
; CHECK: alloca i8*
%arg = alloca { i16*, i32 }, align 8
%2 = bitcast { i16*, i32 }* %0 to i8*
%3 = bitcast { i16*, i32 }* %arg to i8*
call void @llvm.memcpy.p0i8.p0i8.i32(i8* %3, i8* %2, i32 16, i32 8, i1 false)
%b = getelementptr inbounds { i16*, i32 }* %arg, i64 0, i32 0
%pb1 = bitcast i16** %b to i8**
%b1 = load i8** %pb1
%pb0 = bitcast i16** %b to i63*
%b0 = load i63* %pb0
ret void
}