[llvm] f494b36 - [GVN] Don't count debug instructions when limit the number of checked instructions
Guozhi Wei via llvm-commits
llvm-commits at lists.llvm.org
Tue Jan 31 13:04:41 PST 2023
Author: Guozhi Wei
Date: 2023-01-31T21:04:03Z
New Revision: f494b366ff8a076a72a8e1b7a6f401686d6eb0e6
URL: https://github.com/llvm/llvm-project/commit/f494b366ff8a076a72a8e1b7a6f401686d6eb0e6
DIFF: https://github.com/llvm/llvm-project/commit/f494b366ff8a076a72a8e1b7a6f401686d6eb0e6.diff
LOG: [GVN] Don't count debug instructions when limit the number of checked instructions
Don't count debug instructions when limit the number of checked instructions.
Otherwise the debug information may impact optimization like the test case
shows.
Differential Revision: https://reviews.llvm.org/D142787
Added:
llvm/test/Transforms/GVN/PRE/pre-load-dbg.ll
Modified:
llvm/lib/Transforms/Scalar/GVN.cpp
Removed:
################################################################################
diff --git a/llvm/lib/Transforms/Scalar/GVN.cpp b/llvm/lib/Transforms/Scalar/GVN.cpp
index e90db02427dfe..0d52b96df6d09 100644
--- a/llvm/lib/Transforms/Scalar/GVN.cpp
+++ b/llvm/lib/Transforms/Scalar/GVN.cpp
@@ -1369,6 +1369,8 @@ LoadInst *GVNPass::findLoadToHoistIntoPred(BasicBlock *Pred, BasicBlock *LoadBB,
unsigned int NumInsts = MaxNumInsnsPerBlock;
for (Instruction &Inst : *SuccBB) {
+ if (Inst.isDebugOrPseudoInst())
+ continue;
if (--NumInsts == 0)
return nullptr;
diff --git a/llvm/test/Transforms/GVN/PRE/pre-load-dbg.ll b/llvm/test/Transforms/GVN/PRE/pre-load-dbg.ll
new file mode 100644
index 0000000000000..c428a22aea086
--- /dev/null
+++ b/llvm/test/Transforms/GVN/PRE/pre-load-dbg.ll
@@ -0,0 +1,126 @@
+; RUN: opt < %s -passes=gvn -gvn-max-num-insns=22 -S | FileCheck %s
+
+; Debug information should not impact gvn. The following two functions have same
+; code except debug information. They should generate same optimized
+; instructions.
+
+%struct.a = type { i16 }
+
+ at f = local_unnamed_addr global i16 0, align 1
+ at m = local_unnamed_addr global ptr null, align 1
+ at h = global %struct.a zeroinitializer, align 1
+
+define void @withdbg() {
+; CHECK-LABEL: @withdbg
+; CHECK: [[PRE_PRE1:%.*]] = load i16, ptr @f, align 1
+; CHECK-NEXT: [[PRE_PRE2:%.*]] = load ptr, ptr @m, align 1
+; CHECK-NEXT: br i1 true, label %[[BLOCK1:.*]], label %[[BLOCK2:.*]]
+; CHECK: [[BLOCK1]]:
+; CHECK-NEXT: [[CONV:%.*]] = sext i16 [[PRE_PRE1]] to i32
+; CHECK-NEXT: store i32 [[CONV]], ptr [[PRE_PRE2]], align 1
+
+entry:
+ %agg.tmp.ensured.sroa.0.i = alloca i16, align 1
+ br i1 icmp ne (ptr @withdbg, ptr null), label %lor.end, label %lor.rhs
+
+lor.rhs: ; preds = %entry
+ call void @llvm.dbg.declare(metadata ptr undef, metadata !46, metadata !DIExpression()), !dbg !40
+ call void @llvm.dbg.declare(metadata ptr undef, metadata !47, metadata !DIExpression()), !dbg !40
+ call void @llvm.dbg.declare(metadata ptr undef, metadata !48, metadata !DIExpression()), !dbg !40
+ call void @llvm.dbg.declare(metadata ptr undef, metadata !49, metadata !DIExpression()), !dbg !40
+ call void @llvm.dbg.declare(metadata ptr undef, metadata !50, metadata !DIExpression()), !dbg !40
+ %agg.tmp.ensured.sroa.0.0.copyload.i = load volatile i16, ptr @h, align 1
+ store volatile i16 %agg.tmp.ensured.sroa.0.0.copyload.i, ptr %agg.tmp.ensured.sroa.0.i, align 1
+ %agg.tmp.ensured.sroa.0.0.copyload.1.i = load volatile i16, ptr @h, align 1
+ store volatile i16 %agg.tmp.ensured.sroa.0.0.copyload.1.i, ptr %agg.tmp.ensured.sroa.0.i, align 1
+ %agg.tmp.ensured.sroa.0.0.copyload.2.i = load volatile i16, ptr @h, align 1
+ store volatile i16 %agg.tmp.ensured.sroa.0.0.copyload.2.i, ptr %agg.tmp.ensured.sroa.0.i, align 1
+ %agg.tmp.ensured.sroa.0.0.copyload.3.i = load volatile i16, ptr @h, align 1
+ store volatile i16 %agg.tmp.ensured.sroa.0.0.copyload.3.i, ptr %agg.tmp.ensured.sroa.0.i, align 1
+ %agg.tmp.ensured.sroa.0.0.copyload.4.i = load volatile i16, ptr @h, align 1
+ store volatile i16 %agg.tmp.ensured.sroa.0.0.copyload.4.i, ptr %agg.tmp.ensured.sroa.0.i, align 1
+ %agg.tmp.ensured.sroa.0.0.copyload.5.i = load volatile i16, ptr @h, align 1
+ store volatile i16 %agg.tmp.ensured.sroa.0.0.copyload.5.i, ptr %agg.tmp.ensured.sroa.0.i, align 1
+ %agg.tmp.ensured.sroa.0.0.copyload.6.i = load volatile i16, ptr @h, align 1
+ store volatile i16 %agg.tmp.ensured.sroa.0.0.copyload.6.i, ptr %agg.tmp.ensured.sroa.0.i, align 1
+ %agg.tmp.ensured.sroa.0.0.copyload.7.i = load volatile i16, ptr @h, align 1
+ store volatile i16 %agg.tmp.ensured.sroa.0.0.copyload.7.i, ptr %agg.tmp.ensured.sroa.0.i, align 1
+ %agg.tmp.ensured.sroa.0.0.copyload.8.i = load volatile i16, ptr @h, align 1
+ store volatile i16 %agg.tmp.ensured.sroa.0.0.copyload.8.i, ptr %agg.tmp.ensured.sroa.0.i, align 1
+ %fvalue = load i16, ptr @f, align 1
+ %mvalue = load ptr, ptr @m, align 1
+ br label %lor.end
+
+lor.end: ; preds = %lor.rhs, %entry
+ %tmp11 = load i16, ptr @f, align 1
+ %conv.i.i6 = sext i16 %tmp11 to i32
+ %tmp12 = load ptr, ptr @m, align 1
+ store i32 %conv.i.i6, ptr %tmp12, align 1
+ ret void
+}
+
+define void @lessdbg() {
+; CHECK-LABEL: @lessdbg
+; CHECK: [[PRE_PRE1:%.*]] = load i16, ptr @f, align 1
+; CHECK-NEXT: [[PRE_PRE2:%.*]] = load ptr, ptr @m, align 1
+; CHECK-NEXT: br i1 true, label %[[BLOCK1:.*]], label %[[BLOCK2:.*]]
+; CHECK: [[BLOCK1]]:
+; CHECK-NEXT: [[CONV:%.*]] = sext i16 [[PRE_PRE1]] to i32
+; CHECK-NEXT: store i32 [[CONV]], ptr [[PRE_PRE2]], align 1
+
+entry:
+ %agg.tmp.ensured.sroa.0.i = alloca i16, align 1
+ br i1 icmp ne (ptr @lessdbg, ptr null), label %lor.end, label %lor.rhs
+
+lor.rhs: ; preds = %entry
+ %agg.tmp.ensured.sroa.0.0.copyload.i = load volatile i16, ptr @h, align 1
+ store volatile i16 %agg.tmp.ensured.sroa.0.0.copyload.i, ptr %agg.tmp.ensured.sroa.0.i, align 1
+ %agg.tmp.ensured.sroa.0.0.copyload.1.i = load volatile i16, ptr @h, align 1
+ store volatile i16 %agg.tmp.ensured.sroa.0.0.copyload.1.i, ptr %agg.tmp.ensured.sroa.0.i, align 1
+ %agg.tmp.ensured.sroa.0.0.copyload.2.i = load volatile i16, ptr @h, align 1
+ store volatile i16 %agg.tmp.ensured.sroa.0.0.copyload.2.i, ptr %agg.tmp.ensured.sroa.0.i, align 1
+ %agg.tmp.ensured.sroa.0.0.copyload.3.i = load volatile i16, ptr @h, align 1
+ store volatile i16 %agg.tmp.ensured.sroa.0.0.copyload.3.i, ptr %agg.tmp.ensured.sroa.0.i, align 1
+ %agg.tmp.ensured.sroa.0.0.copyload.4.i = load volatile i16, ptr @h, align 1
+ store volatile i16 %agg.tmp.ensured.sroa.0.0.copyload.4.i, ptr %agg.tmp.ensured.sroa.0.i, align 1
+ %agg.tmp.ensured.sroa.0.0.copyload.5.i = load volatile i16, ptr @h, align 1
+ store volatile i16 %agg.tmp.ensured.sroa.0.0.copyload.5.i, ptr %agg.tmp.ensured.sroa.0.i, align 1
+ %agg.tmp.ensured.sroa.0.0.copyload.6.i = load volatile i16, ptr @h, align 1
+ store volatile i16 %agg.tmp.ensured.sroa.0.0.copyload.6.i, ptr %agg.tmp.ensured.sroa.0.i, align 1
+ %agg.tmp.ensured.sroa.0.0.copyload.7.i = load volatile i16, ptr @h, align 1
+ store volatile i16 %agg.tmp.ensured.sroa.0.0.copyload.7.i, ptr %agg.tmp.ensured.sroa.0.i, align 1
+ %agg.tmp.ensured.sroa.0.0.copyload.8.i = load volatile i16, ptr @h, align 1
+ store volatile i16 %agg.tmp.ensured.sroa.0.0.copyload.8.i, ptr %agg.tmp.ensured.sroa.0.i, align 1
+ %fvalue = load i16, ptr @f, align 1
+ %mvalue = load ptr, ptr @m, align 1
+ br label %lor.end
+
+lor.end: ; preds = %lor.rhs, %entry
+ %tmp11 = load i16, ptr @f, align 1
+ %conv.i.i6 = sext i16 %tmp11 to i32
+ %tmp12 = load ptr, ptr @m, align 1
+ store i32 %conv.i.i6, ptr %tmp12, align 1
+ ret void
+}
+
+declare void @llvm.dbg.declare(metadata, metadata, metadata)
+
+!llvm.dbg.cu = !{!0}
+!llvm.module.flags = !{!35, !36}
+
+!0 = distinct !DICompileUnit(language: DW_LANG_C11, file: !1, producer: "clang version 17.0.0.prerel", isOptimized: true, runtimeVersion: 0, emissionKind: FullDebug, splitDebugInlining: false, nameTableKind: None)
+!1 = !DIFile(filename: "bbi-78272.c", directory: "/tmp")
+!5 = !DIBasicType(name: "int", size: 16, encoding: DW_ATE_signed)
+
+!35 = !{i32 7, !"Dwarf Version", i32 4}
+!36 = !{i32 2, !"Debug Info Version", i32 3}
+!40 = !DILocation(line: 15, column: 7, scope: !41)
+!41 = distinct !DISubprogram(name: "x", scope: !1, file: !1, line: 14, type: !42, scopeLine: 14, flags: DIFlagAllCallsDescribed, spFlags: DISPFlagLocalToUnit | DISPFlagDefinition | DISPFlagOptimized, unit: !0, retainedNodes: !45)
+!42 = !DISubroutineType(types: !43)
+!43 = !{!5}
+!45 = !{!46, !47, !48, !49, !50}
+!46 = !DILocalVariable(name: "t", scope: !41, file: !1, line: 15, type: !5)
+!47 = !DILocalVariable(name: "c", scope: !41, file: !1, line: 15, type: !5)
+!48 = !DILocalVariable(name: "v", scope: !41, file: !1, line: 15, type: !5)
+!49 = !DILocalVariable(name: "d", scope: !41, file: !1, line: 15, type: !5)
+!50 = !DILocalVariable(name: "u", scope: !41, file: !1, line: 16, type: !5)
More information about the llvm-commits
mailing list