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| author | Ulrich Weigand <ulrich.weigand@de.ibm.com> | 2017-09-19 20:50:05 +0000 |
|---|---|---|
| committer | Ulrich Weigand <ulrich.weigand@de.ibm.com> | 2017-09-19 20:50:05 +0000 |
| commit | 59a01a958a55c75af4076e35ba67e2a4a38d8dce (patch) | |
| tree | 0d04ddfebf4522b31b99ffc22b605222dd3a5fc1 | |
| parent | 5c37d57e15ddd477fb46992d358fdba5dfd775b0 (diff) | |
| download | bcm5719-llvm-59a01a958a55c75af4076e35ba67e2a4a38d8dce.tar.gz bcm5719-llvm-59a01a958a55c75af4076e35ba67e2a4a38d8dce.zip | |
[SystemZ] Fix truncstore + bswap codegen bug
SystemZTargetLowering::combineSTORE contains code to transform a
combination of STORE + BSWAP into a STRV type instruction.
This transformation is correct for regular stores, but not for
truncating stores. The routine neglected to check for that case.
Fixes a miscompilation of llvm-objcopy with clang, which caused
test suite failures in the SystemZ multistage build bot.
llvm-svn: 313669
| -rw-r--r-- | llvm/lib/Target/SystemZ/SystemZISelLowering.cpp | 3 | ||||
| -rw-r--r-- | llvm/test/CodeGen/SystemZ/bswap-08.ll | 17 |
2 files changed, 19 insertions, 1 deletions
diff --git a/llvm/lib/Target/SystemZ/SystemZISelLowering.cpp b/llvm/lib/Target/SystemZ/SystemZISelLowering.cpp index 1900a00ef26..9e24a3b9548 100644 --- a/llvm/lib/Target/SystemZ/SystemZISelLowering.cpp +++ b/llvm/lib/Target/SystemZ/SystemZISelLowering.cpp @@ -5225,7 +5225,8 @@ SDValue SystemZTargetLowering::combineSTORE( } // Combine STORE (BSWAP) into STRVH/STRV/STRVG // See comment in combineBSWAP about volatile accesses. - if (!SN->isVolatile() && + if (!SN->isTruncatingStore() && + !SN->isVolatile() && Op1.getOpcode() == ISD::BSWAP && Op1.getNode()->hasOneUse() && (Op1.getValueType() == MVT::i16 || diff --git a/llvm/test/CodeGen/SystemZ/bswap-08.ll b/llvm/test/CodeGen/SystemZ/bswap-08.ll new file mode 100644 index 00000000000..f82b09b37b7 --- /dev/null +++ b/llvm/test/CodeGen/SystemZ/bswap-08.ll @@ -0,0 +1,17 @@ +; Verify that truncating stores do not use STRV +; +; RUN: llc < %s -mtriple=s390x-linux-gnu | FileCheck %s + +declare i64 @llvm.bswap.i64(i64) + +define void @f1(i32* %x, i64* %y) { +; CHECK-LABEL: f1: +; CHECK-NOT: strv +; CHECK: br %r14 + %a = load i64, i64* %y, align 8 + %b = tail call i64 @llvm.bswap.i64(i64 %a) + %conv = trunc i64 %b to i32 + store i32 %conv, i32* %x, align 4 + ret void +} + |
