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1; RUN: llc < %s | FileCheck %s --check-prefix=ASM2; RUN: llc -filetype=obj < %s | llvm-readobj --codeview - | FileCheck %s --check-prefix=OBJ3 4; PR388575 6; When stack realignment is required by dynamic allocas are not used, the7; compiler will address locals with the ESP register. However, if call argument8; set up uses PUSH instructions, ESP may vary over the course of the function.9; This means it's not useful as a base register for describing the locations of10; variables. Instead, our CodeView output prefers to use the VFRAME virtual11; register, which is defined in the FPO data as $T0. Make sure we define it.12 13; Original C++ test case, which uses __thiscall to encourage PUSH conversion:14; struct Foo {15; int x = 42;16; int __declspec(noinline) foo();17; void __declspec(noinline) bar(int *a, int *b, ptr c);18; };19; int Foo::foo() {20; int a = 1;21; int b = 2;22; double __declspec(align(8)) force_alignment = 0.42;23; bar(&a, &b, &force_alignment);24; x += (int)force_alignment;25; return x;26; }27; void Foo::bar(int *a, int *b, ptr c) {28; __debugbreak();29; *c += *a + *b;30; }31; int main() {32; Foo o;33; o.foo();34; }35; This stops the debugger in bar, and locals in Foo::foo would be corrupt.36 37; More reduced C code to generate this IR:38; int getval(void);39; void usevals(int *, int *, ptr);40; int realign_with_csrs(int x) {41; int a = getval();42; double __declspec(align(8)) force_alignment = 0.42;43; usevals(&a, &x, &force_alignment);44; return x;45; }46 47; Match the prologue for the .cv_fpo* directives.48; ASM-LABEL: _realign_with_csrs:49; ASM: .cv_fpo_proc _realign_with_csrs 450; ASM: # %bb.0: # %entry51; ASM: pushl %ebp52; ASM: .cv_fpo_pushreg %ebp53; ASM: movl %esp, %ebp54; ASM: .cv_fpo_setframe %ebp55; ASM: andl $-8, %esp56; ASM: .cv_fpo_stackalign 857; ASM: subl $16, %esp58; ASM: .cv_fpo_stackalloc 1659; ASM: .cv_fpo_endprologue60 61; 'x' should be EBP-relative, 'a' and 'force_alignment' ESP relative.62; ASM: calll _getval63; ASM-DAG: leal 8(%esp), %[[LEA_DBL:[^ ]*]]64; ASM-DAG: leal 8(%ebp), %[[LEA_X:[^ ]*]]65; ASM-DAG: leal 4(%esp), %[[LEA_A:[^ ]*]]66; ASM: pushl %[[LEA_DBL]]67; ASM: pushl %[[LEA_X]]68; ASM: pushl %[[LEA_A]]69; ASM: calll _usevals70; ASM: addl $12, %esp71 72; OBJ: Subsection [73; OBJ: SubSectionType: Symbols (0xF1)74; OBJ: ]75; OBJ: Subsection [76; OBJ: SubSectionType: FrameData (0xF5)77; Really, the only important FrameFunc is the last one.78; OBJ: FrameData {79; OBJ: }80; OBJ: FrameData {81; OBJ: }82; OBJ: FrameData {83; OBJ: }84; OBJ: FrameData {85; OBJ: FrameFunc [86; OBJ-NEXT: $T1 $ebp 4 + =87; OBJ-NEXT: $T0 $T1 4 - 8 @ =88; OBJ-NEXT: $eip $T1 ^ =89; OBJ-NEXT: $esp $T1 4 + =90; OBJ-NEXT: $ebp $T1 4 - ^ =91; OBJ-NEXT: ]92; OBJ: }93; OBJ: ]94; OBJ: Subsection [95; OBJ: SubSectionType: Symbols (0xF1)96; OBJ: GlobalProcIdSym {97; OBJ: Kind: S_GPROC32_ID (0x1147)98; OBJ: Flags [ (0x81)99; OBJ: HasFP (0x1)100; OBJ: HasOptimizedDebugInfo (0x80)101; OBJ: ]102; OBJ: DisplayName: realign_with_csrs103; OBJ: LinkageName: _realign_with_csrs104; OBJ: }105; The frame register for locals should be VFRAME, and EBP for parameters.106; OBJ: FrameProcSym {107; OBJ: Kind: S_FRAMEPROC (0x1012)108; OBJ: TotalFrameBytes: 0x14109; OBJ: LocalFramePtrReg: VFRAME (0x7536)110; OBJ: ParamFramePtrReg: EBP (0x16)111; OBJ: }112; As seen in ASM, offset of x is 8.113; OBJ: LocalSym {114; OBJ: Kind: S_LOCAL (0x113E)115; OBJ: Type: int (0x74)116; OBJ: Flags [ (0x1)117; OBJ: IsParameter (0x1)118; OBJ: ]119; OBJ: VarName: x120; OBJ: }121; OBJ: DefRangeFramePointerRelSym {122; OBJ: Kind: S_DEFRANGE_FRAMEPOINTER_REL (0x1142)123; OBJ: Offset: 8124; OBJ: }125; ESP is VFRAME - 16, ESP offset of 'a' is 4, so -12.126; OBJ: LocalSym {127; OBJ: Kind: S_LOCAL (0x113E)128; OBJ: Type: int (0x74)129; OBJ: Flags [ (0x0)130; OBJ: ]131; OBJ: VarName: a132; OBJ: }133; OBJ: DefRangeFramePointerRelSym {134; OBJ: Kind: S_DEFRANGE_FRAMEPOINTER_REL (0x1142)135; OBJ: Offset: -12136; OBJ: }137; ESP is VFRAME - 16, ESP offset of 'force_alignment' is 8, so -8.138; OBJ: LocalSym {139; OBJ: Kind: S_LOCAL (0x113E)140; OBJ: Type: double (0x41)141; OBJ: Flags [ (0x0)142; OBJ: ]143; OBJ: VarName: force_alignment144; OBJ: }145; OBJ: DefRangeFramePointerRelSym {146; OBJ: Kind: S_DEFRANGE_FRAMEPOINTER_REL (0x1142)147; OBJ: Offset: -8148; OBJ: }149; OBJ: ProcEnd {150; OBJ: Kind: S_PROC_ID_END (0x114F)151; OBJ: }152; OBJ: ]153 154; ModuleID = 't.c'155source_filename = "t.c"156target datalayout = "e-m:x-p:32:32-i64:64-f80:32-n8:16:32-a:0:32-S32"157target triple = "i386-pc-windows-msvc19.14.26433"158 159; Function Attrs: nounwind160define dso_local i32 @realign_with_csrs(i32 %x) local_unnamed_addr #0 !dbg !8 {161entry:162 %x.addr = alloca i32, align 4163 %a = alloca i32, align 4164 %force_alignment = alloca double, align 8165 store i32 %x, ptr %x.addr, align 4, !tbaa !17166 call void @llvm.dbg.declare(metadata ptr %x.addr, metadata !13, metadata !DIExpression()), !dbg !21167 call void @llvm.lifetime.start.p0(i64 4, ptr nonnull %a) #4, !dbg !22168 call void @llvm.dbg.declare(metadata ptr %a, metadata !14, metadata !DIExpression()), !dbg !22169 %call = tail call i32 @getval() #4, !dbg !22170 store i32 %call, ptr %a, align 4, !dbg !22, !tbaa !17171 call void @llvm.lifetime.start.p0(i64 8, ptr nonnull %force_alignment) #4, !dbg !23172 call void @llvm.dbg.declare(metadata ptr %force_alignment, metadata !15, metadata !DIExpression()), !dbg !23173 store double 4.200000e-01, ptr %force_alignment, align 8, !dbg !23, !tbaa !24174 call void @usevals(ptr nonnull %a, ptr nonnull %x.addr, ptr nonnull %force_alignment) #4, !dbg !26175 %0 = load i32, ptr %x.addr, align 4, !dbg !27, !tbaa !17176 call void @llvm.lifetime.end.p0(i64 8, ptr nonnull %force_alignment) #4, !dbg !28177 call void @llvm.lifetime.end.p0(i64 4, ptr nonnull %a) #4, !dbg !28178 ret i32 %0, !dbg !27179}180 181; Function Attrs: nounwind readnone speculatable182declare void @llvm.dbg.declare(metadata, metadata, metadata) #1183 184; Function Attrs: argmemonly nounwind185declare void @llvm.lifetime.start.p0(i64, ptr nocapture) #2186 187declare dso_local i32 @getval() local_unnamed_addr #3188 189declare dso_local void @usevals(ptr, ptr, ptr) local_unnamed_addr #3190 191; Function Attrs: argmemonly nounwind192declare void @llvm.lifetime.end.p0(i64, ptr nocapture) #2193 194attributes #0 = { nounwind "correctly-rounded-divide-sqrt-fp-math"="false" "disable-tail-calls"="false" "less-precise-fpmad"="false" "frame-pointer"="none" "no-infs-fp-math"="false" "no-jump-tables"="false" "no-nans-fp-math"="false" "no-signed-zeros-fp-math"="false" "no-trapping-math"="false" "stack-protector-buffer-size"="8" "target-cpu"="pentium4" "target-features"="+fxsr,+mmx,+sse,+sse2,+x87" "use-soft-float"="false" }195attributes #1 = { nounwind readnone speculatable }196attributes #2 = { argmemonly nounwind }197attributes #3 = { "correctly-rounded-divide-sqrt-fp-math"="false" "disable-tail-calls"="false" "less-precise-fpmad"="false" "frame-pointer"="none" "no-infs-fp-math"="false" "no-nans-fp-math"="false" "no-signed-zeros-fp-math"="false" "no-trapping-math"="false" "stack-protector-buffer-size"="8" "target-cpu"="pentium4" "target-features"="+fxsr,+mmx,+sse,+sse2,+x87" "use-soft-float"="false" }198attributes #4 = { nounwind }199 200!llvm.dbg.cu = !{!0}201!llvm.module.flags = !{!3, !4, !5, !6}202!llvm.ident = !{!7}203 204!0 = distinct !DICompileUnit(language: DW_LANG_C99, file: !1, producer: "clang version 8.0.0 ", isOptimized: true, runtimeVersion: 0, emissionKind: FullDebug, enums: !2, nameTableKind: None)205!1 = !DIFile(filename: "t.c", directory: "C:\5Csrc\5Cllvm-project\5Cbuild", checksumkind: CSK_MD5, checksum: "a646950309d5d01d8087fc10fea33941")206!2 = !{}207!3 = !{i32 1, !"NumRegisterParameters", i32 0}208!4 = !{i32 2, !"CodeView", i32 1}209!5 = !{i32 2, !"Debug Info Version", i32 3}210!6 = !{i32 1, !"wchar_size", i32 2}211!7 = !{!"clang version 8.0.0 "}212!8 = distinct !DISubprogram(name: "realign_with_csrs", scope: !1, file: !1, line: 3, type: !9, isLocal: false, isDefinition: true, scopeLine: 3, flags: DIFlagPrototyped, isOptimized: true, unit: !0, retainedNodes: !12)213!9 = !DISubroutineType(types: !10)214!10 = !{!11, !11}215!11 = !DIBasicType(name: "int", size: 32, encoding: DW_ATE_signed)216!12 = !{!13, !14, !15}217!13 = !DILocalVariable(name: "x", arg: 1, scope: !8, file: !1, line: 3, type: !11)218!14 = !DILocalVariable(name: "a", scope: !8, file: !1, line: 4, type: !11)219!15 = !DILocalVariable(name: "force_alignment", scope: !8, file: !1, line: 5, type: !16, align: 64)220!16 = !DIBasicType(name: "double", size: 64, encoding: DW_ATE_float)221!17 = !{!18, !18, i64 0}222!18 = !{!"int", !19, i64 0}223!19 = !{!"omnipotent char", !20, i64 0}224!20 = !{!"Simple C/C++ TBAA"}225!21 = !DILocation(line: 3, scope: !8)226!22 = !DILocation(line: 4, scope: !8)227!23 = !DILocation(line: 5, scope: !8)228!24 = !{!25, !25, i64 0}229!25 = !{!"double", !19, i64 0}230!26 = !DILocation(line: 6, scope: !8)231!27 = !DILocation(line: 7, scope: !8)232!28 = !DILocation(line: 8, scope: !8)233