[llvm] r327372 - [MergeICmps] Make sure that the comparison only has one use.
Clement Courbet via llvm-commits
llvm-commits at lists.llvm.org
Tue Mar 13 00:05:56 PDT 2018
Author: courbet
Date: Tue Mar 13 00:05:55 2018
New Revision: 327372
URL: http://llvm.org/viewvc/llvm-project?rev=327372&view=rev
Log:
[MergeICmps] Make sure that the comparison only has one use.
Summary: Fixes PR36557.
Reviewers: trentxintong, spatel
Subscribers: mstorsjo, llvm-commits
Differential Revision: https://reviews.llvm.org/D44083
Added:
llvm/trunk/test/Transforms/MergeICmps/X86/pr36557.ll
Modified:
llvm/trunk/lib/Transforms/Scalar/MergeICmps.cpp
Modified: llvm/trunk/lib/Transforms/Scalar/MergeICmps.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Transforms/Scalar/MergeICmps.cpp?rev=327372&r1=327371&r2=327372&view=diff
==============================================================================
--- llvm/trunk/lib/Transforms/Scalar/MergeICmps.cpp (original)
+++ llvm/trunk/lib/Transforms/Scalar/MergeICmps.cpp Tue Mar 13 00:05:55 2018
@@ -177,6 +177,15 @@ bool BCECmpBlock::doesOtherWork() const
// BCE atoms, returns the comparison.
BCECmpBlock visitICmp(const ICmpInst *const CmpI,
const ICmpInst::Predicate ExpectedPredicate) {
+ // The comparison can only be used once:
+ // - For intermediate blocks, as a branch condition.
+ // - For the final block, as an incoming value for the Phi.
+ // If there are any other uses of the comparison, we cannot merge it with
+ // other comparisons as we would create an orphan use of the value.
+ if (!CmpI->hasOneUse()) {
+ DEBUG(dbgs() << "cmp has several uses\n");
+ return {};
+ }
if (CmpI->getPredicate() == ExpectedPredicate) {
DEBUG(dbgs() << "cmp "
<< (ExpectedPredicate == ICmpInst::ICMP_EQ ? "eq" : "ne")
Added: llvm/trunk/test/Transforms/MergeICmps/X86/pr36557.ll
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/Transforms/MergeICmps/X86/pr36557.ll?rev=327372&view=auto
==============================================================================
--- llvm/trunk/test/Transforms/MergeICmps/X86/pr36557.ll (added)
+++ llvm/trunk/test/Transforms/MergeICmps/X86/pr36557.ll Tue Mar 13 00:05:55 2018
@@ -0,0 +1,100 @@
+; NOTE: Assertions have been autogenerated by utils/update_test_checks.py
+; RUN: opt < %s -mergeicmps -mtriple=x86_64-unknown-unknown -S | FileCheck %s --check-prefix=X86
+
+source_filename = "qabstractitemmodeltester.cpp"
+target datalayout = "e-m:e-i64:64-f80:128-n8:16:32:64-S128"
+target triple = "x86_64--linux-gnu"
+
+%class.B = type { i32, i32 }
+%class.D = type { i32 }
+%class.C = type { i8 }
+%class.QMessageLogger = type { i8 }
+
+$_ZN1D7compareI1BS1_EEbRKT_RKT0_PKcS9_S9_i = comdat any
+
+ at .str = private unnamed_addr constant [1 x i8] zeroinitializer, align 1
+
+; Function Attrs: uwtable
+define linkonce_odr dso_local zeroext i1 @_ZN1D7compareI1BS1_EEbRKT_RKT0_PKcS9_S9_i(%class.D* %this, %class.B* dereferenceable(8) %p1, %class.B* dereferenceable(8) %p2, i8*, i8*, i8*, i32) local_unnamed_addr #0 comdat align 2 {
+; X86-LABEL: @_ZN1D7compareI1BS1_EEbRKT_RKT0_PKcS9_S9_i(
+; X86-NEXT: entry:
+; X86-NEXT: [[REF_TMP:%.*]] = alloca [[CLASS_C:%.*]], align 1
+; X86-NEXT: [[C_I:%.*]] = getelementptr inbounds [[CLASS_B:%.*]], %class.B* [[P2:%.*]], i64 0, i32 0
+; X86-NEXT: [[TMP4:%.*]] = load i32, i32* [[C_I]], align 4
+; X86-NEXT: [[C2_I:%.*]] = getelementptr inbounds [[CLASS_B]], %class.B* [[P1:%.*]], i64 0, i32 0
+; X86-NEXT: [[TMP5:%.*]] = load i32, i32* [[C2_I]], align 4
+; X86-NEXT: [[CMP_ENTRY:%.*]] = icmp eq i32 [[TMP4]], [[TMP5]]
+; X86-NEXT: br i1 [[CMP_ENTRY]], label [[BB1:%.*]], label [[BB2:%.*]]
+; X86: bb1:
+; X86-NEXT: [[M_I:%.*]] = getelementptr inbounds [[CLASS_B]], %class.B* [[P2]], i64 0, i32 1
+; X86-NEXT: [[TMP6:%.*]] = load i32, i32* [[M_I]], align 4
+; X86-NEXT: [[M3_I:%.*]] = getelementptr inbounds [[CLASS_B]], %class.B* [[P1]], i64 0, i32 1
+; X86-NEXT: [[TMP7:%.*]] = load i32, i32* [[M3_I]], align 4
+; X86-NEXT: [[CMP1:%.*]] = icmp eq i32 [[TMP6]], [[TMP7]]
+; X86-NEXT: br label [[BB2]]
+; X86: bb2:
+; X86-NEXT: [[TMP8:%.*]] = phi i1 [ false, [[ENTRY:%.*]] ], [ [[CMP1]], [[BB1]] ]
+; X86-NEXT: [[FAILUREREPORTINGMODE:%.*]] = getelementptr inbounds [[CLASS_D:%.*]], %class.D* [[THIS:%.*]], i64 0, i32 0
+; X86-NEXT: [[TMP9:%.*]] = load i32, i32* [[FAILUREREPORTINGMODE]], align 4
+; X86-NEXT: [[COND:%.*]] = icmp eq i32 [[TMP9]], 0
+; X86-NEXT: br i1 [[COND]], label [[BB3:%.*]], label [[SW_EPILOG:%.*]]
+; X86: bb3:
+; X86-NEXT: br i1 [[CMP_ENTRY]], label [[BB4:%.*]], label [[BB5:%.*]]
+; X86: bb4:
+; X86-NEXT: [[M_I_I:%.*]] = getelementptr inbounds [[CLASS_B]], %class.B* [[P2]], i64 0, i32 1
+; X86-NEXT: [[TMP10:%.*]] = load i32, i32* [[M_I_I]], align 4
+; X86-NEXT: [[M3_I_I:%.*]] = getelementptr inbounds [[CLASS_B]], %class.B* [[P1]], i64 0, i32 1
+; X86-NEXT: [[TMP11:%.*]] = load i32, i32* [[M3_I_I]], align 4
+; X86-NEXT: [[CMP4:%.*]] = icmp eq i32 [[TMP10]], [[TMP11]]
+; X86-NEXT: br label [[BB5]]
+; X86: bb5:
+; X86-NEXT: [[TMP12:%.*]] = phi i1 [ false, [[BB3]] ], [ [[CMP4]], [[BB4]] ]
+; X86-NEXT: [[TMP13:%.*]] = getelementptr inbounds [[CLASS_C]], %class.C* [[REF_TMP]], i64 0, i32 0
+; X86-NEXT: br label [[SW_EPILOG]]
+; X86: sw.epilog:
+; X86-NEXT: ret i1 [[TMP8]]
+;
+entry:
+ %ref.tmp = alloca %class.C, align 1
+ %c.i = getelementptr inbounds %class.B, %class.B* %p2, i64 0, i32 0
+ %4 = load i32, i32* %c.i, align 4
+ %c2.i = getelementptr inbounds %class.B, %class.B* %p1, i64 0, i32 0
+ %5 = load i32, i32* %c2.i, align 4
+ %cmp_entry = icmp eq i32 %4, %5
+ br i1 %cmp_entry, label %bb1, label %bb2
+
+bb1: ; preds = %entry
+ %m.i = getelementptr inbounds %class.B, %class.B* %p2, i64 0, i32 1
+ %6 = load i32, i32* %m.i, align 4
+ %m3.i = getelementptr inbounds %class.B, %class.B* %p1, i64 0, i32 1
+ %7 = load i32, i32* %m3.i, align 4
+ %cmp1 = icmp eq i32 %6, %7
+ br label %bb2
+
+bb2: ; preds = %entry, %bb1
+ %8 = phi i1 [ false, %entry ], [ %cmp1, %bb1 ]
+ %failureReportingMode = getelementptr inbounds %class.D, %class.D* %this, i64 0, i32 0
+ %9 = load i32, i32* %failureReportingMode, align 4
+ %cond = icmp eq i32 %9, 0
+ br i1 %cond, label %bb3, label %sw.epilog
+
+bb3: ; preds = %bb2
+ br i1 %cmp_entry, label %bb4, label %bb5
+
+bb4: ; preds = %bb3
+ %m.i.i = getelementptr inbounds %class.B, %class.B* %p2, i64 0, i32 1
+ %10 = load i32, i32* %m.i.i, align 4
+ %m3.i.i = getelementptr inbounds %class.B, %class.B* %p1, i64 0, i32 1
+ %11 = load i32, i32* %m3.i.i, align 4
+ %cmp4 = icmp eq i32 %10, %11
+ br label %bb5
+
+bb5: ; preds = %bb3, %bb4
+ %12 = phi i1 [ false, %bb3 ], [ %cmp4, %bb4 ]
+ %13 = getelementptr inbounds %class.C, %class.C* %ref.tmp, i64 0, i32 0
+ br label %sw.epilog
+
+sw.epilog: ; preds = %bb2
+ ret i1 %8
+}
+
More information about the llvm-commits
mailing list