[llvm] r320606 - Ignore metainstructions during the shrink wrap analysis
Adrian Prantl via llvm-commits
llvm-commits at lists.llvm.org
Wed Dec 13 11:10:54 PST 2017
Author: adrian
Date: Wed Dec 13 11:10:54 2017
New Revision: 320606
URL: http://llvm.org/viewvc/llvm-project?rev=320606&view=rev
Log:
Ignore metainstructions during the shrink wrap analysis
Shrink wrapping should ignore DBG_VALUEs referring to frame indices,
since the presence of debug information must not affect code
generation.
Differential Revision: https://reviews.llvm.org/D41187
Added:
llvm/trunk/test/CodeGen/MIR/X86/shrink_wrap_dbg_value.mir
Modified:
llvm/trunk/lib/CodeGen/ShrinkWrap.cpp
Modified: llvm/trunk/lib/CodeGen/ShrinkWrap.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/CodeGen/ShrinkWrap.cpp?rev=320606&r1=320605&r2=320606&view=diff
==============================================================================
--- llvm/trunk/lib/CodeGen/ShrinkWrap.cpp (original)
+++ llvm/trunk/lib/CodeGen/ShrinkWrap.cpp Wed Dec 13 11:10:54 2017
@@ -240,6 +240,10 @@ INITIALIZE_PASS_END(ShrinkWrap, DEBUG_TY
bool ShrinkWrap::useOrDefCSROrFI(const MachineInstr &MI,
RegScavenger *RS) const {
+ // Ignore DBG_VALUE and other meta instructions that must not affect codegen.
+ if (MI.isMetaInstruction())
+ return false;
+
if (MI.getOpcode() == FrameSetupOpcode ||
MI.getOpcode() == FrameDestroyOpcode) {
DEBUG(dbgs() << "Frame instruction: " << MI << '\n');
Added: llvm/trunk/test/CodeGen/MIR/X86/shrink_wrap_dbg_value.mir
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/CodeGen/MIR/X86/shrink_wrap_dbg_value.mir?rev=320606&view=auto
==============================================================================
--- llvm/trunk/test/CodeGen/MIR/X86/shrink_wrap_dbg_value.mir (added)
+++ llvm/trunk/test/CodeGen/MIR/X86/shrink_wrap_dbg_value.mir Wed Dec 13 11:10:54 2017
@@ -0,0 +1,182 @@
+# RUN: llc -o - %s -run-pass=shrink-wrap | FileCheck %s
+--- |
+ ; ModuleID = '<stdin>'
+ source_filename = "t.c"
+ target datalayout = "e-m:x-p:32:32-i64:64-f80:32-n8:16:32-a:0:32-S32"
+ target triple = "i386-pc-windows-msvc19.11.25508"
+
+ ; Function Attrs: nounwind
+ define x86_fastcallcc i32 @"@shrink_wrap_basic at 16"(i32 inreg %a, i32 inreg %b, i32 %c, i32 %d) local_unnamed_addr #0 !dbg !8 {
+ entry:
+ %c.addr = alloca i32, align 4
+ tail call void @llvm.dbg.value(metadata i32 %d, metadata !13, metadata !DIExpression()), !dbg !19
+ tail call void @llvm.dbg.value(metadata i32 %c, metadata !14, metadata !DIExpression()), !dbg !20
+ store i32 %c, i32* %c.addr, align 4, !tbaa !21
+ tail call void @llvm.dbg.value(metadata i32 %b, metadata !15, metadata !DIExpression()), !dbg !25
+ tail call void @llvm.dbg.value(metadata i32 %a, metadata !16, metadata !DIExpression()), !dbg !26
+ %cmp = icmp slt i32 %a, %b, !dbg !27
+ br i1 %cmp, label %return, label %for.cond.preheader, !dbg !29
+
+ for.cond.preheader: ; preds = %entry
+ %0 = add i32 %c, -1, !dbg !30
+ br label %for.cond, !dbg !30
+
+ for.cond: ; preds = %for.cond, %for.cond.preheader
+ %lsr.iv = phi i32 [ %lsr.iv.next, %for.cond ], [ %0, %for.cond.preheader ]
+ call void @llvm.dbg.value(metadata i32 undef, metadata !17, metadata !DIExpression()), !dbg !32
+ call void @llvm.dbg.value(metadata i32* %c.addr, metadata !14, metadata !DIExpression()), !dbg !20
+ %call = call i32 @doSomething(i32* nonnull %c.addr) #3, !dbg !33
+ call void @llvm.dbg.value(metadata !2, metadata !17, metadata !DIExpression()), !dbg !32
+ %lsr.iv.next = add i32 %lsr.iv, 1, !dbg !30
+ %cmp1 = icmp slt i32 %lsr.iv.next, %d, !dbg !30
+ br i1 %cmp1, label %for.cond, label %return, !dbg !34, !llvm.loop !35
+
+ return: ; preds = %for.cond, %entry
+ %retval.0 = phi i32 [ %a, %entry ], [ %call, %for.cond ]
+ ret i32 %retval.0, !dbg !37
+ }
+
+ declare i32 @doSomething(i32*) local_unnamed_addr
+
+ ; Function Attrs: nounwind readnone speculatable
+ declare void @llvm.dbg.value(metadata, metadata, metadata) #2
+
+ ; Function Attrs: nounwind
+ declare void @llvm.stackprotector(i8*, i8**) #3
+
+ attributes #0 = { nounwind }
+ attributes #2 = { nounwind readnone speculatable }
+ attributes #3 = { nounwind }
+
+ !llvm.dbg.cu = !{!0}
+ !llvm.module.flags = !{!3, !4, !5, !6}
+ !llvm.ident = !{!7}
+
+ !0 = distinct !DICompileUnit(language: DW_LANG_C99, file: !1, producer: "clang version 6.0.0 ", isOptimized: true, runtimeVersion: 0, emissionKind: FullDebug, enums: !2)
+ !1 = !DIFile(filename: "t.c", directory: "C:\5Csrc\5Cllvm-project\5Cbuild", checksumkind: CSK_MD5, checksum: "32f118fd5dd7e65ff7733c49b2f804ef")
+ !2 = !{}
+ !3 = !{i32 1, !"NumRegisterParameters", i32 0}
+ !4 = !{i32 2, !"CodeView", i32 1}
+ !5 = !{i32 2, !"Debug Info Version", i32 3}
+ !6 = !{i32 1, !"wchar_size", i32 2}
+ !7 = !{!"clang version 6.0.0 "}
+ !8 = distinct !DISubprogram(name: "shrink_wrap_basic", linkageName: "\01 at shrink_wrap_basic@16", scope: !1, file: !1, line: 2, type: !9, isLocal: false, isDefinition: true, scopeLine: 2, flags: DIFlagPrototyped, isOptimized: true, unit: !0, variables: !12)
+ !9 = !DISubroutineType(cc: DW_CC_BORLAND_msfastcall, types: !10)
+ !10 = !{!11, !11, !11, !11, !11}
+ !11 = !DIBasicType(name: "int", size: 32, encoding: DW_ATE_signed)
+ !12 = !{!13, !14, !15, !16, !17}
+ !13 = !DILocalVariable(name: "d", arg: 4, scope: !8, file: !1, line: 2, type: !11)
+ !14 = !DILocalVariable(name: "c", arg: 3, scope: !8, file: !1, line: 2, type: !11)
+ !15 = !DILocalVariable(name: "b", arg: 2, scope: !8, file: !1, line: 2, type: !11)
+ !16 = !DILocalVariable(name: "a", arg: 1, scope: !8, file: !1, line: 2, type: !11)
+ !17 = !DILocalVariable(name: "i", scope: !18, file: !1, line: 5, type: !11)
+ !18 = distinct !DILexicalBlock(scope: !8, file: !1, line: 5, column: 3)
+ !19 = !DILocation(line: 2, column: 59, scope: !8)
+ !20 = !DILocation(line: 2, column: 52, scope: !8)
+ !21 = !{!22, !22, i64 0}
+ !22 = !{!"int", !23, i64 0}
+ !23 = !{!"omnipotent char", !24, i64 0}
+ !24 = !{!"Simple C/C++ TBAA"}
+ !25 = !DILocation(line: 2, column: 45, scope: !8)
+ !26 = !DILocation(line: 2, column: 38, scope: !8)
+ !27 = !DILocation(line: 3, column: 9, scope: !28)
+ !28 = distinct !DILexicalBlock(scope: !8, file: !1, line: 3, column: 7)
+ !29 = !DILocation(line: 3, column: 7, scope: !8)
+ !30 = !DILocation(line: 5, column: 21, scope: !31)
+ !31 = distinct !DILexicalBlock(scope: !18, file: !1, line: 5, column: 3)
+ !32 = !DILocation(line: 5, column: 12, scope: !18)
+ !33 = !DILocation(line: 0, scope: !8)
+ !34 = !DILocation(line: 5, column: 3, scope: !18)
+ !35 = distinct !{!35, !34, !36}
+ !36 = !DILocation(line: 6, column: 19, scope: !18)
+ !37 = !DILocation(line: 8, column: 1, scope: !8)
+
+...
+---
+name: '@shrink_wrap_basic at 16'
+alignment: 4
+exposesReturnsTwice: false
+legalized: false
+regBankSelected: false
+selected: false
+tracksRegLiveness: true
+registers:
+liveins:
+ - { reg: '%ecx', virtual-reg: '' }
+ - { reg: '%edx', virtual-reg: '' }
+frameInfo:
+ isFrameAddressTaken: false
+ isReturnAddressTaken: false
+ hasStackMap: false
+ hasPatchPoint: false
+ stackSize: 0
+ offsetAdjustment: 0
+ maxAlignment: 4
+ adjustsStack: false
+ hasCalls: true
+ stackProtector: ''
+ maxCallFrameSize: 4294967295
+ hasOpaqueSPAdjustment: false
+ hasVAStart: false
+ hasMustTailInVarArgFunc: false
+ # CHECK: savePoint: '%bb.1'
+ # CHECK: restorePoint: '%bb.3'
+ savePoint: ''
+ restorePoint: ''
+fixedStack:
+ - { id: 0, type: default, offset: 4, size: 4, alignment: 4, stack-id: 0,
+ isImmutable: true, isAliased: false, callee-saved-register: '', callee-saved-restored: true }
+ - { id: 1, type: default, offset: 0, size: 4, alignment: 4, stack-id: 0,
+ isImmutable: false, isAliased: false, callee-saved-register: '',
+ callee-saved-restored: true }
+stack:
+constants:
+body: |
+ bb.0.entry:
+ successors: %bb.4(0x40000000), %bb.1(0x40000000)
+ liveins: %ecx, %edx
+
+ DBG_VALUE debug-use %edx, debug-use %noreg, !15, !DIExpression(), debug-location !25
+ DBG_VALUE debug-use %ecx, debug-use %noreg, !16, !DIExpression(), debug-location !26
+ %eax = COPY %ecx
+ DBG_VALUE %fixed-stack.0, 0, !16, !DIExpression(), debug-location !26
+ DBG_VALUE %fixed-stack.1, 0, !15, !DIExpression(), debug-location !25
+ CMP32rr %eax, killed %edx, implicit-def %eflags, debug-location !27
+ JL_1 %bb.4, implicit killed %eflags, debug-location !29
+ JMP_1 %bb.1, debug-location !29
+
+ bb.1.for.cond.preheader:
+ successors: %bb.2(0x80000000)
+
+ %esi = MOV32rm %fixed-stack.0, 1, %noreg, 0, %noreg :: (load 4 from %fixed-stack.0)
+ DBG_VALUE debug-use %esi, debug-use %noreg, !13, !DIExpression(), debug-location !19
+ %edi = MOV32rm %fixed-stack.1, 1, %noreg, 0, %noreg :: (load 4 from %fixed-stack.1)
+ DBG_VALUE debug-use %edi, debug-use %noreg, !14, !DIExpression(), debug-location !20
+ %edi = DEC32r killed %edi, implicit-def dead %eflags, debug-location !30
+ %ebx = LEA32r %fixed-stack.1, 1, %noreg, 0, %noreg
+
+ bb.2.for.cond:
+ successors: %bb.2(0x7c000000), %bb.3(0x04000000)
+ liveins: %ebx, %edi, %esi
+
+ ADJCALLSTACKDOWN32 4, 0, 4, implicit-def dead %esp, implicit-def dead %eflags, implicit-def dead %ssp, implicit %esp, implicit %ssp, debug-location !33
+ DBG_VALUE %fixed-stack.1, 0, !14, !DIExpression(), debug-location !20
+ PUSH32r %ebx, implicit-def %esp, implicit %esp, debug-location !33
+ ;CFI_INSTRUCTION <unserializable cfi operation>, debug-location !33
+ CALLpcrel32 @doSomething, csr_32, implicit %esp, implicit %ssp, implicit-def %esp, implicit-def %ssp, implicit-def %eax, debug-location !33
+ ADJCALLSTACKUP32 4, 0, implicit-def dead %esp, implicit-def dead %eflags, implicit-def dead %ssp, implicit %esp, implicit %ssp, debug-location !33
+ %edi = INC32r killed %edi, implicit-def dead %eflags, debug-location !30
+ CMP32rr %edi, %esi, implicit-def %eflags, debug-location !30
+ JL_1 %bb.2, implicit killed %eflags, debug-location !34
+
+ bb.3:
+ successors: %bb.4(0x80000000)
+ liveins: %eax
+
+
+ bb.4.return:
+ liveins: %eax
+
+ RET 8, %eax, debug-location !37
+
+...
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