llvm/test/CodeGen/X86/2009-02-12-DebugInfoVLA.ll
Tim Shen e7221e673c [SSP, 2/2] Create llvm.stackguard() intrinsic and lower it to LOAD_STACK_GUARD
With this change, ideally IR pass can always generate llvm.stackguard
call to get the stack guard; but for now there are still IR form stack
guard customizations around (see getIRStackGuard()). Future SSP
customization should go through LOAD_STACK_GUARD.

There is a behavior change: stack guard values are not CSEed anymore,
since we should never reuse the value in case that it has been spilled (and
corrupted). See ssp-guard-spill.ll. This also cause the change of stack
size and codegen in X86 and AArch64 test cases.

Ideally we'd like to know if the guard created in llvm.stackprotector() gets
spilled or not. If the value is spilled, discard the value and reload
stack guard; otherwise reuse the value. This can be done by teaching
register allocator to know how to rematerialize LOAD_STACK_GUARD and
force a rematerialization (which seems hard), or check for spilling in
expandPostRAPseudo. It only makes sense when the stack guard is a global
variable, which requires more instructions to load. Anyway, this seems to go out
of the scope of the current patch.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@266806 91177308-0d34-0410-b5e6-96231b3b80d8
2016-04-19 19:40:37 +00:00

99 lines
5.3 KiB
LLVM

; RUN: llc < %s
; RUN: llc < %s -stack-symbol-ordering=0 -march=x86-64 -verify-machineinstrs | FileCheck %s
; PR3538
target datalayout = "e-p:32:32:32-i1:8:8-i8:8:8-i16:16:16-i32:32:32-i64:32:64-f32:32:32-f64:32:64-v64:64:64-v128:128:128-a0:0:64-f80:128:128"
target triple = "i386-apple-darwin9"
define signext i8 @foo(i8* %s1) nounwind ssp {
; Make sure we generate:
; movq -40(%rbp), %rsp
; Instead of:
; movq -40(%rbp), %rax
; movq %rax, %rsp
; CHECK-LABEL: @foo
; CHECK: movq -{{[0-9]+}}(%rbp), %rsp
entry:
%s1_addr = alloca i8* ; <i8**> [#uses=2]
%retval = alloca i32 ; <i32*> [#uses=2]
%saved_stack.1 = alloca i8* ; <i8**> [#uses=2]
%0 = alloca i32 ; <i32*> [#uses=2]
%str.0 = alloca [0 x i8]* ; <[0 x i8]**> [#uses=3]
%1 = alloca i64 ; <i64*> [#uses=2]
%2 = alloca i64 ; <i64*> [#uses=1]
%3 = alloca i64 ; <i64*> [#uses=6]
%"alloca point" = bitcast i32 0 to i32 ; <i32> [#uses=0]
call void @llvm.dbg.declare(metadata i8** %s1_addr, metadata !0, metadata !DIExpression()), !dbg !7
store i8* %s1, i8** %s1_addr
call void @llvm.dbg.declare(metadata [0 x i8]** %str.0, metadata !8, metadata !DIExpression()), !dbg !7
%4 = call i8* @llvm.stacksave(), !dbg !7 ; <i8*> [#uses=1]
store i8* %4, i8** %saved_stack.1, align 8, !dbg !7
%5 = load i8*, i8** %s1_addr, align 8, !dbg !13 ; <i8*> [#uses=1]
%6 = call i64 @strlen(i8* %5) nounwind readonly, !dbg !13 ; <i64> [#uses=1]
%7 = add i64 %6, 1, !dbg !13 ; <i64> [#uses=1]
store i64 %7, i64* %3, align 8, !dbg !13
%8 = load i64, i64* %3, align 8, !dbg !13 ; <i64> [#uses=1]
%9 = sub nsw i64 %8, 1, !dbg !13 ; <i64> [#uses=0]
%10 = load i64, i64* %3, align 8, !dbg !13 ; <i64> [#uses=1]
%11 = mul i64 %10, 8, !dbg !13 ; <i64> [#uses=0]
%12 = load i64, i64* %3, align 8, !dbg !13 ; <i64> [#uses=1]
store i64 %12, i64* %2, align 8, !dbg !13
%13 = load i64, i64* %3, align 8, !dbg !13 ; <i64> [#uses=1]
%14 = mul i64 %13, 8, !dbg !13 ; <i64> [#uses=0]
%15 = load i64, i64* %3, align 8, !dbg !13 ; <i64> [#uses=1]
store i64 %15, i64* %1, align 8, !dbg !13
%16 = load i64, i64* %1, align 8, !dbg !13 ; <i64> [#uses=1]
%17 = trunc i64 %16 to i32, !dbg !13 ; <i32> [#uses=1]
%18 = alloca i8, i32 %17, !dbg !13 ; <i8*> [#uses=1]
%19 = bitcast i8* %18 to [0 x i8]*, !dbg !13 ; <[0 x i8]*> [#uses=1]
store [0 x i8]* %19, [0 x i8]** %str.0, align 8, !dbg !13
%20 = load [0 x i8]*, [0 x i8]** %str.0, align 8, !dbg !15 ; <[0 x i8]*> [#uses=1]
%21 = getelementptr inbounds [0 x i8], [0 x i8]* %20, i64 0, i64 0, !dbg !15 ; <i8*> [#uses=1]
store i8 0, i8* %21, align 1, !dbg !15
%22 = load [0 x i8]*, [0 x i8]** %str.0, align 8, !dbg !16 ; <[0 x i8]*> [#uses=1]
%23 = getelementptr inbounds [0 x i8], [0 x i8]* %22, i64 0, i64 0, !dbg !16 ; <i8*> [#uses=1]
%24 = load i8, i8* %23, align 1, !dbg !16 ; <i8> [#uses=1]
%25 = sext i8 %24 to i32, !dbg !16 ; <i32> [#uses=1]
store i32 %25, i32* %0, align 4, !dbg !16
%26 = load i8*, i8** %saved_stack.1, align 8, !dbg !16 ; <i8*> [#uses=1]
call void @llvm.stackrestore(i8* %26), !dbg !16
%27 = load i32, i32* %0, align 4, !dbg !16 ; <i32> [#uses=1]
store i32 %27, i32* %retval, align 4, !dbg !16
br label %return, !dbg !16
return: ; preds = %entry
%retval1 = load i32, i32* %retval, !dbg !16 ; <i32> [#uses=1]
%retval12 = trunc i32 %retval1 to i8, !dbg !16 ; <i8> [#uses=1]
ret i8 %retval12, !dbg !16
}
declare void @llvm.dbg.declare(metadata, metadata, metadata) nounwind readnone
declare i8* @llvm.stacksave() nounwind
declare i64 @strlen(i8*) nounwind readonly
declare void @llvm.stackrestore(i8*) nounwind
!llvm.dbg.cu = !{!2}
!0 = !DILocalVariable(name: "s1", line: 2, arg: 1, scope: !1, file: !2, type: !6)
!1 = distinct !DISubprogram(name: "foo", linkageName: "foo", line: 2, isLocal: false, isDefinition: true, virtualIndex: 6, isOptimized: false, unit: !2, scope: !2, type: !3)
!2 = distinct !DICompileUnit(language: DW_LANG_C89, producer: "4.2.1 (Based on Apple Inc. build 5658) (LLVM build)", isOptimized: true, emissionKind: FullDebug, file: !17, enums: !18, retainedTypes: !18)
!3 = !DISubroutineType(types: !4)
!4 = !{!5, !6}
!5 = !DIBasicType(tag: DW_TAG_base_type, name: "char", size: 8, align: 8, encoding: DW_ATE_signed_char)
!6 = !DIDerivedType(tag: DW_TAG_pointer_type, size: 64, align: 64, scope: !2, baseType: !5)
!7 = !DILocation(line: 2, scope: !1)
!8 = !DILocalVariable(name: "str.0", line: 3, scope: !1, file: !2, type: !9)
!9 = !DIDerivedType(tag: DW_TAG_pointer_type, size: 64, align: 64, flags: DIFlagArtificial, scope: !2, baseType: !10)
!10 = !DICompositeType(tag: DW_TAG_array_type, size: 8, align: 8, scope: !2, baseType: !5, elements: !11)
!11 = !{!12}
!12 = !DISubrange(count: 1)
!13 = !DILocation(line: 3, scope: !14)
!14 = distinct !DILexicalBlock(line: 0, column: 0, file: !17, scope: !1)
!15 = !DILocation(line: 4, scope: !14)
!16 = !DILocation(line: 5, scope: !14)
!17 = !DIFile(filename: "vla.c", directory: "/tmp/")
!18 = !{i32 0}