[llvm] 23817cb - [SCEVExpander] Make sure cast properly dominates Builder's IP.
Florian Hahn via llvm-commits
llvm-commits at lists.llvm.org
Sun Aug 9 08:56:03 PDT 2020
Author: Florian Hahn
Date: 2020-08-09T16:51:19+01:00
New Revision: 23817cbd0b6549d6145e4d0dbc0162370184a21e
URL: https://github.com/llvm/llvm-project/commit/23817cbd0b6549d6145e4d0dbc0162370184a21e
DIFF: https://github.com/llvm/llvm-project/commit/23817cbd0b6549d6145e4d0dbc0162370184a21e.diff
LOG: [SCEVExpander] Make sure cast properly dominates Builder's IP.
The selected cast must properly dominate the Builder's IP, so we cannot
re-use the cast, if it matches the builder's IP.
Added:
llvm/test/Transforms/LoopStrengthReduce/X86/expander-crashes.ll
Modified:
llvm/lib/Transforms/Utils/ScalarEvolutionExpander.cpp
Removed:
################################################################################
diff --git a/llvm/lib/Transforms/Utils/ScalarEvolutionExpander.cpp b/llvm/lib/Transforms/Utils/ScalarEvolutionExpander.cpp
index ade2cfa30dd0..da6a719dccd1 100644
--- a/llvm/lib/Transforms/Utils/ScalarEvolutionExpander.cpp
+++ b/llvm/lib/Transforms/Utils/ScalarEvolutionExpander.cpp
@@ -65,8 +65,9 @@ Value *SCEVExpander::ReuseOrCreateCast(Value *V, Type *Ty,
if (!CI || CI->getOpcode() != Op)
continue;
- // Found a suitable cast that is at IP or comes before IP. Use it.
- if (IP->getParent() == CI->getParent() &&
+ // Found a suitable cast that is at IP or comes before IP. Use it. Note that
+ // the cast must also properly dominate the Builder's insertion point.
+ if (IP->getParent() == CI->getParent() && &*BIP != CI &&
(&*IP == CI || CI->comesBefore(&*IP))) {
Ret = CI;
break;
diff --git a/llvm/test/Transforms/LoopStrengthReduce/X86/expander-crashes.ll b/llvm/test/Transforms/LoopStrengthReduce/X86/expander-crashes.ll
new file mode 100644
index 000000000000..c895a10ba110
--- /dev/null
+++ b/llvm/test/Transforms/LoopStrengthReduce/X86/expander-crashes.ll
@@ -0,0 +1,85 @@
+; NOTE: Assertions have been autogenerated by utils/update_test_checks.py
+; RUN: opt -loop-reduce %s -S | FileCheck %s
+
+target datalayout = "e-m:o-p270:32:32-p271:32:32-p272:64:64-i64:64-f80:128-n8:16:32:64-S128"
+target triple = "x86_64-apple-macosx10.15.0"
+
+; Tests for crashes during SCEV expansion.
+
+%struct.hoge = type { i32, i32, i32, i32 }
+
+define i64 @blam(%struct.hoge* %start, %struct.hoge* %end, %struct.hoge* %ptr.2) {
+; CHECK-LABEL: @blam(
+; CHECK-NEXT: entry:
+; CHECK-NEXT: [[END16:%.*]] = bitcast %struct.hoge* [[END:%.*]] to i8*
+; CHECK-NEXT: [[START17:%.*]] = ptrtoint %struct.hoge* [[START:%.*]] to i64
+; CHECK-NEXT: [[SCEVGEP12:%.*]] = getelementptr [[STRUCT_HOGE:%.*]], %struct.hoge* [[START]], i64 0, i32 3
+; CHECK-NEXT: [[SCEVGEP1213:%.*]] = bitcast i32* [[SCEVGEP12]] to %struct.hoge*
+; CHECK-NEXT: [[TMP0:%.*]] = sub i64 0, [[START17]]
+; CHECK-NEXT: [[UGLYGEP18:%.*]] = getelementptr i8, i8* [[END16]], i64 [[TMP0]]
+; CHECK-NEXT: [[UGLYGEP1819:%.*]] = bitcast i8* [[UGLYGEP18]] to %struct.hoge*
+; CHECK-NEXT: br label [[LOOP_1_HEADER:%.*]]
+; CHECK: loop.1.header:
+; CHECK-NEXT: [[LSR_IV20:%.*]] = phi %struct.hoge* [ [[SCEVGEP21:%.*]], [[LOOP_1_HEADER]] ], [ [[UGLYGEP1819]], [[ENTRY:%.*]] ]
+; CHECK-NEXT: [[LSR_IV14:%.*]] = phi %struct.hoge* [ [[SCEVGEP15:%.*]], [[LOOP_1_HEADER]] ], [ [[SCEVGEP1213]], [[ENTRY]] ]
+; CHECK-NEXT: [[SCEVGEP15]] = getelementptr [[STRUCT_HOGE]], %struct.hoge* [[LSR_IV14]], i64 1
+; CHECK-NEXT: [[SCEVGEP21]] = getelementptr [[STRUCT_HOGE]], %struct.hoge* [[LSR_IV20]], i64 -1
+; CHECK-NEXT: [[EC:%.*]] = icmp eq %struct.hoge* [[SCEVGEP21]], null
+; CHECK-NEXT: br i1 [[EC]], label [[LOOP_2_PH:%.*]], label [[LOOP_1_HEADER]]
+; CHECK: loop.2.ph:
+; CHECK-NEXT: br label [[LOOP_2_HEADER:%.*]]
+; CHECK: loop.2.header:
+; CHECK-NEXT: [[LSR_IV3:%.*]] = phi %struct.hoge* [ [[SCEVGEP4:%.*]], [[LOOP_2_LATCH:%.*]] ], [ [[SCEVGEP15]], [[LOOP_2_PH]] ]
+; CHECK-NEXT: [[LSR_IV310:%.*]] = bitcast %struct.hoge* [[LSR_IV3]] to i32*
+; CHECK-NEXT: [[LSR_IV37:%.*]] = bitcast %struct.hoge* [[LSR_IV3]] to i8*
+; CHECK-NEXT: [[UGLYGEP8:%.*]] = getelementptr i8, i8* [[LSR_IV37]], i64 -12
+; CHECK-NEXT: [[UGLYGEP89:%.*]] = bitcast i8* [[UGLYGEP8]] to %struct.hoge*
+; CHECK-NEXT: [[LSR_IV35:%.*]] = bitcast %struct.hoge* [[LSR_IV3]] to i8*
+; CHECK-NEXT: [[TMP8:%.*]] = ptrtoint i32* [[LSR_IV310]] to i64
+; CHECK-NEXT: call void @use.i64(i64 [[TMP8]])
+; CHECK-NEXT: [[SCEVGEP11:%.*]] = getelementptr i32, i32* [[LSR_IV310]], i64 -1
+; CHECK-NEXT: store i32 10, i32* [[SCEVGEP11]], align 8
+; CHECK-NEXT: [[EC_2:%.*]] = icmp ugt %struct.hoge* [[UGLYGEP89]], [[PTR_2:%.*]]
+; CHECK-NEXT: br i1 [[EC_2]], label [[LOOP_2_EXIT:%.*]], label [[LOOP_2_LATCH]]
+; CHECK: loop.2.latch:
+; CHECK-NEXT: [[SCEVGEP4]] = getelementptr [[STRUCT_HOGE]], %struct.hoge* [[LSR_IV3]], i64 1
+; CHECK-NEXT: br label [[LOOP_2_HEADER]]
+; CHECK: loop.2.exit:
+; CHECK-NEXT: [[UGLYGEP:%.*]] = getelementptr i8, i8* [[LSR_IV35]], i64 -12
+; CHECK-NEXT: [[UGLYGEP6:%.*]] = bitcast i8* [[UGLYGEP]] to %struct.hoge*
+; CHECK-NEXT: [[IV2_CAST:%.*]] = ptrtoint %struct.hoge* [[UGLYGEP6]] to i64
+; CHECK-NEXT: ret i64 [[IV2_CAST]]
+;
+entry:
+ br label %loop.1.header
+
+loop.1.header:
+ %iv = phi %struct.hoge* [ %iv.next, %loop.1.header ], [ %start, %entry ]
+ %iv.next = getelementptr inbounds %struct.hoge, %struct.hoge* %iv, i64 1
+ %ec = icmp eq %struct.hoge* %iv.next, %end
+ br i1 %ec, label %loop.2.ph, label %loop.1.header
+
+loop.2.ph:
+ br label %loop.2.header
+
+loop.2.header:
+ %iv2 = phi %struct.hoge* [ %iv2.next, %loop.2.latch ], [ %iv.next, %loop.2.ph ]
+ %tmp7 = getelementptr inbounds %struct.hoge, %struct.hoge* %iv2, i64 0, i32 3
+ %tmp8 = ptrtoint i32* %tmp7 to i64
+ call void @use.i64(i64 %tmp8)
+ %tmp9 = getelementptr inbounds %struct.hoge, %struct.hoge* %iv2, i64 0, i32 2
+ store i32 10, i32* %tmp9, align 8
+ %ec.2 = icmp ugt %struct.hoge* %iv2, %ptr.2
+ br i1 %ec.2, label %loop.2.exit, label %loop.2.latch
+
+loop.2.latch:
+ %iv2.next = getelementptr inbounds %struct.hoge, %struct.hoge* %iv2, i64 1
+ br label %loop.2.header
+
+loop.2.exit: ; preds = %bb6
+ %iv2.cast = ptrtoint %struct.hoge* %iv2 to i64
+ ret i64 %iv2.cast
+}
+
+
+declare void @use.i64(i64)
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