From 73686d305a99750bb61202565b6bc73d74103bfb Mon Sep 17 00:00:00 2001 From: "Duncan P. N. Exon Smith" Date: Tue, 17 Jun 2014 00:19:35 +0000 Subject: SROA: Only split loads on byte boundaries MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit 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 llvm-svn: 211082 --- llvm/test/Transforms/SROA/slice-width.ll | 25 +++++++++++++++++++++++++ 1 file changed, 25 insertions(+) create mode 100644 llvm/test/Transforms/SROA/slice-width.ll (limited to 'llvm/test/Transforms/SROA/slice-width.ll') diff --git a/llvm/test/Transforms/SROA/slice-width.ll b/llvm/test/Transforms/SROA/slice-width.ll new file mode 100644 index 00000000000..179780b4afe --- /dev/null +++ b/llvm/test/Transforms/SROA/slice-width.ll @@ -0,0 +1,25 @@ +; 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 + +define void @no_split_on_non_byte_width(i32) { +; This tests that allocas are not split into slices that are not byte width multiple + %arg = alloca i32 , align 8 + store i32 %0, i32* %arg + br label %load_i32 + +load_i32: +; CHECK-LABEL: load_i32: +; CHECK-NOT: bitcast {{.*}} to i1 +; CHECK-NOT: zext i1 + %r0 = load i32* %arg + br label %load_i1 + +load_i1: +; CHECK-LABEL: load_i1: +; CHECK: bitcast {{.*}} to i1 + %p1 = bitcast i32* %arg to i1* + %t1 = load i1* %p1 + ret void +} -- cgit v1.2.3