[llvm-commits] [llvm] r145273 - in /llvm/trunk: lib/CodeGen/SelectionDAG/DAGCombiner.cpp test/CodeGen/ARM/2011-11-28-DAGCombineBug.ll test/CodeGen/X86/widen_load-1.ll
Evan Cheng
evan.cheng at apple.com
Mon Nov 28 12:42:57 PST 2011
Author: evancheng
Date: Mon Nov 28 14:42:56 2011
New Revision: 145273
URL: http://llvm.org/viewvc/llvm-project?rev=145273&view=rev
Log:
DAG combine should not increase alignment of loads / stores with alignment less
than ABI alignment. These are loads / stores from / to "packed" data structures.
Their alignments are intentionally under-specified.
rdar://10301431
Added:
llvm/trunk/test/CodeGen/ARM/2011-11-28-DAGCombineBug.ll
Modified:
llvm/trunk/lib/CodeGen/SelectionDAG/DAGCombiner.cpp
llvm/trunk/test/CodeGen/X86/widen_load-1.ll
Modified: llvm/trunk/lib/CodeGen/SelectionDAG/DAGCombiner.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/CodeGen/SelectionDAG/DAGCombiner.cpp?rev=145273&r1=145272&r2=145273&view=diff
==============================================================================
--- llvm/trunk/lib/CodeGen/SelectionDAG/DAGCombiner.cpp (original)
+++ llvm/trunk/lib/CodeGen/SelectionDAG/DAGCombiner.cpp Mon Nov 28 14:42:56 2011
@@ -6206,13 +6206,20 @@
// Try to infer better alignment information than the load already has.
if (OptLevel != CodeGenOpt::None && LD->isUnindexed()) {
- if (unsigned Align = DAG.InferPtrAlignment(Ptr)) {
- if (Align > LD->getAlignment())
- return DAG.getExtLoad(LD->getExtensionType(), N->getDebugLoc(),
- LD->getValueType(0),
- Chain, Ptr, LD->getPointerInfo(),
- LD->getMemoryVT(),
- LD->isVolatile(), LD->isNonTemporal(), Align);
+ unsigned ABIAlign = TLI.getTargetData()->
+ getABITypeAlignment(LD->getMemoryVT().getTypeForEVT(*DAG.getContext()));
+ unsigned LDAlign = LD->getAlignment();
+ // Do not touch loads with explicit alignments that are smaller than ABI
+ // alignment to avoid breaking loads from "packed" types.
+ if (!LDAlign || LDAlign >= ABIAlign) {
+ if (unsigned Align = DAG.InferPtrAlignment(Ptr)) {
+ if (Align > LDAlign)
+ return DAG.getExtLoad(LD->getExtensionType(), N->getDebugLoc(),
+ LD->getValueType(0),
+ Chain, Ptr, LD->getPointerInfo(),
+ LD->getMemoryVT(),
+ LD->isVolatile(), LD->isNonTemporal(), Align);
+ }
}
}
@@ -6669,11 +6676,18 @@
// Try to infer better alignment information than the store already has.
if (OptLevel != CodeGenOpt::None && ST->isUnindexed()) {
- if (unsigned Align = DAG.InferPtrAlignment(Ptr)) {
- if (Align > ST->getAlignment())
- return DAG.getTruncStore(Chain, N->getDebugLoc(), Value,
- Ptr, ST->getPointerInfo(), ST->getMemoryVT(),
- ST->isVolatile(), ST->isNonTemporal(), Align);
+ unsigned ABIAlign = TLI.getTargetData()->
+ getABITypeAlignment(ST->getMemoryVT().getTypeForEVT(*DAG.getContext()));
+ unsigned STAlign = ST->getAlignment();
+ // Do not touch stores with explicit alignments that are smaller than ABI
+ // alignment to avoid breaking stores from "packed" types.
+ if (!STAlign || STAlign >= ABIAlign) {
+ if (unsigned Align = DAG.InferPtrAlignment(Ptr)) {
+ if (Align > STAlign)
+ return DAG.getTruncStore(Chain, N->getDebugLoc(), Value,
+ Ptr, ST->getPointerInfo(), ST->getMemoryVT(),
+ ST->isVolatile(), ST->isNonTemporal(),Align);
+ }
}
}
Added: llvm/trunk/test/CodeGen/ARM/2011-11-28-DAGCombineBug.ll
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/CodeGen/ARM/2011-11-28-DAGCombineBug.ll?rev=145273&view=auto
==============================================================================
--- llvm/trunk/test/CodeGen/ARM/2011-11-28-DAGCombineBug.ll (added)
+++ llvm/trunk/test/CodeGen/ARM/2011-11-28-DAGCombineBug.ll Mon Nov 28 14:42:56 2011
@@ -0,0 +1,38 @@
+; RUN: llc < %s -mtriple=thumbv7-apple-ios5.0.0 | FileCheck %s
+; rdar://10464621
+
+; DAG combine increases loads from packed types. ARM load / store optimizer then
+; combined them into a ldm which causes runtime exception.
+
+%struct.InformationBlock = type <{ i32, %struct.FlagBits, %struct.FlagBits }>
+%struct.FlagBits = type <{ [4 x i32] }>
+
+ at infoBlock = external global %struct.InformationBlock
+
+define hidden void @foo() {
+; CHECK: foo:
+; CHECK: ldr.w
+; CHECK: ldr.w
+; CHECK-NOT: ldm
+entry:
+ %tmp13 = load i32* getelementptr inbounds (%struct.InformationBlock* @infoBlock, i32 0, i32 1, i32 0, i32 0), align 1
+ %tmp15 = load i32* getelementptr inbounds (%struct.InformationBlock* @infoBlock, i32 0, i32 1, i32 0, i32 1), align 1
+ %tmp17 = load i32* getelementptr inbounds (%struct.InformationBlock* @infoBlock, i32 0, i32 1, i32 0, i32 2), align 1
+ %tmp19 = load i32* getelementptr inbounds (%struct.InformationBlock* @infoBlock, i32 0, i32 1, i32 0, i32 3), align 1
+ %tmp = load i32* getelementptr inbounds (%struct.InformationBlock* @infoBlock, i32 0, i32 2, i32 0, i32 0), align 1
+ %tmp3 = load i32* getelementptr inbounds (%struct.InformationBlock* @infoBlock, i32 0, i32 2, i32 0, i32 1), align 1
+ %tmp4 = load i32* getelementptr inbounds (%struct.InformationBlock* @infoBlock, i32 0, i32 2, i32 0, i32 2), align 1
+ %tmp5 = load i32* getelementptr inbounds (%struct.InformationBlock* @infoBlock, i32 0, i32 2, i32 0, i32 3), align 1
+ %insert21 = insertvalue [4 x i32] undef, i32 %tmp13, 0
+ %insert23 = insertvalue [4 x i32] %insert21, i32 %tmp15, 1
+ %insert25 = insertvalue [4 x i32] %insert23, i32 %tmp17, 2
+ %insert27 = insertvalue [4 x i32] %insert25, i32 %tmp19, 3
+ %insert = insertvalue [4 x i32] undef, i32 %tmp, 0
+ %insert7 = insertvalue [4 x i32] %insert, i32 %tmp3, 1
+ %insert9 = insertvalue [4 x i32] %insert7, i32 %tmp4, 2
+ %insert11 = insertvalue [4 x i32] %insert9, i32 %tmp5, 3
+ tail call void @bar([4 x i32] %insert27, [4 x i32] %insert11)
+ ret void
+}
+
+declare void @bar([4 x i32], [4 x i32])
Modified: llvm/trunk/test/CodeGen/X86/widen_load-1.ll
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/CodeGen/X86/widen_load-1.ll?rev=145273&r1=145272&r2=145273&view=diff
==============================================================================
--- llvm/trunk/test/CodeGen/X86/widen_load-1.ll (original)
+++ llvm/trunk/test/CodeGen/X86/widen_load-1.ll Mon Nov 28 14:42:56 2011
@@ -1,5 +1,6 @@
; RUN: llc %s -o - -march=x86-64 -mtriple=x86_64-unknown-linux-gnu | FileCheck %s
; PR4891
+; PR5626
; This load should be before the call, not after.
@@ -20,7 +21,7 @@
store i32 0, i32* %changed, align 4
%r2 = getelementptr float* bitcast ([20 x i64]* @compl to float*), i64 32 ; <float*> [#uses=1]
%r3 = bitcast float* %r2 to <2 x float>* ; <<2 x float>*> [#uses=1]
- %r4 = load <2 x float>* %r3, align 4 ; <<2 x float>> [#uses=1]
+ %r4 = load <2 x float>* %r3, align 8 ; <<2 x float>> [#uses=1]
call void @killcommon(i32* %changed)
br label %"file complex.c, line 34, bb4"
More information about the llvm-commits
mailing list