[llvm] r327971 - [MergeICmp] Fix a bug in entry block shuffled to middle of the chain
Xin Tong via llvm-commits
llvm-commits at lists.llvm.org
Tue Mar 20 04:57:55 PDT 2018
Author: trentxintong
Date: Tue Mar 20 04:57:54 2018
New Revision: 327971
URL: http://llvm.org/viewvc/llvm-project?rev=327971&view=rev
Log:
[MergeICmp] Fix a bug in entry block shuffled to middle of the chain
Summary: Fix a bug in entry block shuffled to middle of the chain.
Reviewers: davide, courbet
Subscribers: llvm-commits
Differential Revision: https://reviews.llvm.org/D44642
Added:
llvm/trunk/test/Transforms/MergeICmps/X86/entry-block-shuffled.ll
Modified:
llvm/trunk/lib/Transforms/Scalar/MergeICmps.cpp
llvm/trunk/test/Transforms/MergeICmps/X86/pair-int32-int32.ll
Modified: llvm/trunk/lib/Transforms/Scalar/MergeICmps.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Transforms/Scalar/MergeICmps.cpp?rev=327971&r1=327970&r2=327971&view=diff
==============================================================================
--- llvm/trunk/lib/Transforms/Scalar/MergeICmps.cpp (original)
+++ llvm/trunk/lib/Transforms/Scalar/MergeICmps.cpp Tue Mar 20 04:57:54 2018
@@ -403,6 +403,17 @@ bool BCECmpChain::simplify(const TargetL
Phi_.removeIncomingValue(Comparison.BB, false);
}
+ // If entry block is part of the chain, we need to make the first block
+ // of the chain the new entry block of the function.
+ BasicBlock *Entry = &Comparisons_[0].BB->getParent()->getEntryBlock();
+ for (size_t I = 1; I < Comparisons_.size(); ++I) {
+ if (Entry == Comparisons_[I].BB) {
+ BasicBlock *NEntryBB = BasicBlock::Create(Entry->getContext(), "",
+ Entry->getParent(), Entry);
+ BranchInst::Create(Entry, NEntryBB);
+ }
+ }
+
// Point the predecessors of the chain to the first comparison block (which is
// the new entry point).
if (EntryBlock_ != Comparisons_[0].BB)
Added: llvm/trunk/test/Transforms/MergeICmps/X86/entry-block-shuffled.ll
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/Transforms/MergeICmps/X86/entry-block-shuffled.ll?rev=327971&view=auto
==============================================================================
--- llvm/trunk/test/Transforms/MergeICmps/X86/entry-block-shuffled.ll (added)
+++ llvm/trunk/test/Transforms/MergeICmps/X86/entry-block-shuffled.ll Tue Mar 20 04:57:54 2018
@@ -0,0 +1,56 @@
+; NOTE: Assertions have been autogenerated by utils/update_test_checks.py
+; RUN: opt < %s -mergeicmps -mtriple=x86_64-unknown-unknown -S | FileCheck %s
+
+%"struct.std::pair" = type { i32, i32, i32, i32 }
+
+; The entry block is part of the chain. It however can not be merged. We need to make the
+; first comparison block in the chain the new entry block of the function.
+
+define zeroext i1 @opeq1(
+; CHECK-LABEL: @opeq1(
+; CHECK-NEXT: br label [[LAND_RHS_I:%.*]]
+; CHECK: land.rhs.i:
+; CHECK-NEXT: [[SECOND_I:%.*]] = getelementptr inbounds %"struct.std::pair", %"struct.std::pair"* %a, i64 0, i32 0
+; CHECK-NEXT: [[SECOND2_I:%.*]] = getelementptr inbounds %"struct.std::pair", %"struct.std::pair"* %b, i64 0, i32 0
+; CHECK-NEXT: [[CSTR:%.*]] = bitcast i32* [[SECOND_I]] to i8*
+; CHECK-NEXT: [[CSTR1:%.*]] = bitcast i32* [[SECOND2_I]] to i8*
+; CHECK-NEXT: [[MEMCMP:%.*]] = call i32 @memcmp(i8* [[CSTR]], i8* [[CSTR1]], i64 8)
+;
+ %"struct.std::pair"* nocapture readonly dereferenceable(16) %a,
+ %"struct.std::pair"* nocapture readonly dereferenceable(16) %b) local_unnamed_addr #0 {
+entry:
+ %first.i = getelementptr inbounds %"struct.std::pair", %"struct.std::pair"* %a, i64 0, i32 3
+ %0 = load i32, i32* %first.i, align 4
+ %first1.i = getelementptr inbounds %"struct.std::pair", %"struct.std::pair"* %b, i64 0, i32 2
+ %1 = load i32, i32* %first1.i, align 4
+ %cmp.i = icmp eq i32 %0, %1
+ br i1 %cmp.i, label %land.rhs.i, label %opeq1.exit
+
+land.rhs.i:
+ %second.i = getelementptr inbounds %"struct.std::pair", %"struct.std::pair"* %a, i64 0, i32 0
+ %2 = load i32, i32* %second.i, align 4
+ %second2.i = getelementptr inbounds %"struct.std::pair", %"struct.std::pair"* %b, i64 0, i32 0
+ %3 = load i32, i32* %second2.i, align 4
+ %cmp3.i = icmp eq i32 %2, %3
+ br i1 %cmp3.i, label %land.rhs.i.2, label %opeq1.exit
+
+land.rhs.i.2:
+ %third.i = getelementptr inbounds %"struct.std::pair", %"struct.std::pair"* %a, i64 0, i32 1
+ %4 = load i32, i32* %third.i, align 4
+ %third2.i = getelementptr inbounds %"struct.std::pair", %"struct.std::pair"* %b, i64 0, i32 1
+ %5 = load i32, i32* %third2.i, align 4
+ %cmp4.i = icmp eq i32 %4, %5
+ br i1 %cmp4.i, label %land.rhs.i.3, label %opeq1.exit
+
+land.rhs.i.3:
+ %fourth.i = getelementptr inbounds %"struct.std::pair", %"struct.std::pair"* %a, i64 0, i32 3
+ %6 = load i32, i32* %fourth.i, align 4
+ %fourth2.i = getelementptr inbounds %"struct.std::pair", %"struct.std::pair"* %b, i64 0, i32 3
+ %7 = load i32, i32* %fourth2.i, align 4
+ %cmp5.i = icmp eq i32 %6, %7
+ br label %opeq1.exit
+
+opeq1.exit:
+ %8 = phi i1 [ false, %entry ], [ false, %land.rhs.i], [ false, %land.rhs.i.2 ], [ %cmp5.i, %land.rhs.i.3 ]
+ ret i1 %8
+}
Modified: llvm/trunk/test/Transforms/MergeICmps/X86/pair-int32-int32.ll
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/Transforms/MergeICmps/X86/pair-int32-int32.ll?rev=327971&r1=327970&r2=327971&view=diff
==============================================================================
--- llvm/trunk/test/Transforms/MergeICmps/X86/pair-int32-int32.ll (original)
+++ llvm/trunk/test/Transforms/MergeICmps/X86/pair-int32-int32.ll Tue Mar 20 04:57:54 2018
@@ -47,7 +47,8 @@ opeq1.exit:
; Same as above, but the two blocks are in inverse order.
define zeroext i1 @opeq1_inverse(
; X86-LABEL: @opeq1_inverse(
-; X86-NEXT: land.rhs.i:
+; X86-NEXT: br label [[LAND_RHS_I:%.*]]
+; X86: land.rhs.i:
; X86-NEXT: [[SECOND_I:%.*]] = getelementptr inbounds %"struct.std::pair", %"struct.std::pair"* [[A:%.*]], i64 0, i32 0
; X86-NEXT: [[SECOND2_I:%.*]] = getelementptr inbounds %"struct.std::pair", %"struct.std::pair"* [[B:%.*]], i64 0, i32 0
; X86-NEXT: [[CSTR:%.*]] = bitcast i32* [[SECOND_I]] to i8*
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