llvm/test/CodeGen/ARM/debug-frame-vararg.ll
Tim Northover 52f83a9ab3 ARM: simplify and extend byval handling
The main issue being fixed here is that APCS targets handling a "byval align N"
parameter with N > 4 were miscounting what objects were where on the stack,
leading to FrameLowering setting the frame pointer incorrectly and clobbering
the stack.

But byval handling had grown over many years, and had multiple layers of cruft
trying to compensate for each other and calculate padding correctly. This only
really needs to be done once, in the HandleByVal function. Elsewhere should
just do what it's told by that call.

I also stripped out unnecessary APCS/AAPCS distinctions (now that Clang emits
byvals with the correct C ABI alignment), which simplified HandleByVal.

rdar://20095672

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@231959 91177308-0d34-0410-b5e6-96231b3b80d8
2015-03-11 18:54:22 +00:00

141 lines
5.8 KiB
LLVM

; RUN: llc -mtriple arm-unknown-linux-gnueabi -filetype asm -o - %s | FileCheck %s --check-prefix=CHECK-FP
; RUN: llc -mtriple arm-unknown-linux-gnueabi -filetype asm -o - %s -disable-fp-elim | FileCheck %s --check-prefix=CHECK-FP-ELIM
; RUN: llc -mtriple thumb-unknown-linux-gnueabi -filetype asm -o - %s | FileCheck %s --check-prefix=CHECK-THUMB-FP
; RUN: llc -mtriple thumb-unknown-linux-gnueabi -filetype asm -o - %s -disable-fp-elim | FileCheck %s --check-prefix=CHECK-THUMB-FP-ELIM
; Tests that the initial space allocated to the varargs on the stack is
; taken into account in the the .cfi_ directives.
; Generated from the C program:
; #include <stdarg.h>
;
; extern int foo(int);
;
; int sum(int count, ...) {
; va_list vl;
; va_start(vl, count);
; int sum = 0;
; for (int i = 0; i < count; i++) {
; sum += foo(va_arg(vl, int));
; }
; va_end(vl);
; }
!llvm.dbg.cu = !{!0}
!llvm.module.flags = !{!9, !10}
!llvm.ident = !{!11}
!0 = !MDCompileUnit(language: DW_LANG_C99, producer: "clang version 3.5 ", isOptimized: false, emissionKind: 0, file: !1, enums: !2, retainedTypes: !2, subprograms: !3, globals: !2, imports: !2)
!1 = !MDFile(filename: "var.c", directory: "/tmp")
!2 = !{}
!3 = !{!4}
!4 = !MDSubprogram(name: "sum", line: 5, isLocal: false, isDefinition: true, virtualIndex: 6, flags: DIFlagPrototyped, isOptimized: false, scopeLine: 5, file: !1, scope: !5, type: !6, function: i32 (i32, ...)* @sum, variables: !2)
!5 = !MDFile(filename: "var.c", directory: "/tmp")
!6 = !MDSubroutineType(types: !7)
!7 = !{!8, !8}
!8 = !MDBasicType(tag: DW_TAG_base_type, name: "int", size: 32, align: 32, encoding: DW_ATE_signed)
!9 = !{i32 2, !"Dwarf Version", i32 4}
!10 = !{i32 1, !"Debug Info Version", i32 3}
!11 = !{!"clang version 3.5 "}
!12 = !MDLocalVariable(tag: DW_TAG_arg_variable, name: "count", line: 5, arg: 1, scope: !4, file: !5, type: !8)
!13 = !MDLocation(line: 5, scope: !4)
!14 = !MDLocalVariable(tag: DW_TAG_auto_variable, name: "vl", line: 6, scope: !4, file: !5, type: !15)
!15 = !MDDerivedType(tag: DW_TAG_typedef, name: "va_list", line: 30, file: !16, baseType: !17)
!16 = !MDFile(filename: "/linux-x86_64-high/gcc_4.7.2/dbg/llvm/bin/../lib/clang/3.5/include/stdarg.h", directory: "/tmp")
!17 = !MDDerivedType(tag: DW_TAG_typedef, name: "__builtin_va_list", line: 6, file: !1, baseType: !18)
!18 = !MDCompositeType(tag: DW_TAG_structure_type, name: "__va_list", line: 6, size: 32, align: 32, file: !1, elements: !19)
!19 = !{!20}
!20 = !MDDerivedType(tag: DW_TAG_member, name: "__ap", line: 6, size: 32, align: 32, file: !1, scope: !18, baseType: !21)
!21 = !MDDerivedType(tag: DW_TAG_pointer_type, size: 32, align: 32, baseType: null)
!22 = !MDLocation(line: 6, scope: !4)
!23 = !MDLocation(line: 7, scope: !4)
!24 = !MDLocalVariable(tag: DW_TAG_auto_variable, name: "sum", line: 8, scope: !4, file: !5, type: !8)
!25 = !MDLocation(line: 8, scope: !4)
!26 = !MDLocalVariable(tag: DW_TAG_auto_variable, name: "i", line: 9, scope: !27, file: !5, type: !8)
!27 = distinct !MDLexicalBlock(line: 9, column: 0, file: !1, scope: !4)
!28 = !MDLocation(line: 9, scope: !27)
!29 = !MDLocation(line: 10, scope: !30)
!30 = distinct !MDLexicalBlock(line: 9, column: 0, file: !1, scope: !27)
!31 = !MDLocation(line: 11, scope: !30)
!32 = !MDLocation(line: 12, scope: !4)
!33 = !MDLocation(line: 13, scope: !4)
; CHECK-FP-LABEL: sum
; CHECK-FP: .cfi_startproc
; CHECK-FP: sub sp, sp, #12
; CHECK-FP: .cfi_def_cfa_offset 12
; CHECK-FP: push {r4, lr}
; CHECK-FP: .cfi_def_cfa_offset 20
; CHECK-FP: .cfi_offset lr, -16
; CHECK-FP: .cfi_offset r4, -20
; CHECK-FP: sub sp, sp, #4
; CHECK-FP: .cfi_def_cfa_offset 24
; CHECK-FP-ELIM-LABEL: sum
; CHECK-FP-ELIM: .cfi_startproc
; CHECK-FP-ELIM: sub sp, sp, #12
; CHECK-FP-ELIM: .cfi_def_cfa_offset 12
; CHECK-FP-ELIM: push {r4, r10, r11, lr}
; CHECK-FP-ELIM: .cfi_def_cfa_offset 28
; CHECK-FP-ELIM: .cfi_offset lr, -16
; CHECK-FP-ELIM: .cfi_offset r11, -20
; CHECK-FP-ELIM: .cfi_offset r10, -24
; CHECK-FP-ELIM: .cfi_offset r4, -28
; CHECK-FP-ELIM: add r11, sp, #8
; CHECK-FP-ELIM: .cfi_def_cfa r11, 20
; CHECK-THUMB-FP-LABEL: sum
; CHECK-THUMB-FP: .cfi_startproc
; CHECK-THUMB-FP: sub sp, #12
; CHECK-THUMB-FP: .cfi_def_cfa_offset 12
; CHECK-THUMB-FP: push {r4, lr}
; CHECK-THUMB-FP: .cfi_def_cfa_offset 20
; CHECK-THUMB-FP: .cfi_offset lr, -16
; CHECK-THUMB-FP: .cfi_offset r4, -20
; CHECK-THUMB-FP: sub sp, #4
; CHECK-THUMB-FP: .cfi_def_cfa_offset 24
; CHECK-THUMB-FP-ELIM-LABEL: sum
; CHECK-THUMB-FP-ELIM: .cfi_startproc
; CHECK-THUMB-FP-ELIM: sub sp, #12
; CHECK-THUMB-FP-ELIM: .cfi_def_cfa_offset 12
; CHECK-THUMB-FP-ELIM: push {r4, r6, r7, lr}
; CHECK-THUMB-FP-ELIM: .cfi_def_cfa_offset 28
; CHECK-THUMB-FP-ELIM: .cfi_offset lr, -16
; CHECK-THUMB-FP-ELIM: .cfi_offset r7, -20
; CHECK-THUMB-FP-ELIM: .cfi_offset r6, -24
; CHECK-THUMB-FP-ELIM: .cfi_offset r4, -28
; CHECK-THUMB-FP-ELIM: add r7, sp, #8
; CHECK-THUMB-FP-ELIM: .cfi_def_cfa r7, 20
define i32 @sum(i32 %count, ...) {
entry:
%vl = alloca i8*, align 4
%vl1 = bitcast i8** %vl to i8*
call void @llvm.va_start(i8* %vl1)
%cmp4 = icmp sgt i32 %count, 0
br i1 %cmp4, label %for.body, label %for.end
for.body: ; preds = %entry, %for.body
%i.05 = phi i32 [ %inc, %for.body ], [ 0, %entry ]
%ap.cur = load i8*, i8** %vl, align 4
%ap.next = getelementptr i8, i8* %ap.cur, i32 4
store i8* %ap.next, i8** %vl, align 4
%0 = bitcast i8* %ap.cur to i32*
%1 = load i32, i32* %0, align 4
%call = call i32 @foo(i32 %1) #1
%inc = add nsw i32 %i.05, 1
%exitcond = icmp eq i32 %inc, %count
br i1 %exitcond, label %for.end, label %for.body
for.end: ; preds = %for.body, %entry
call void @llvm.va_end(i8* %vl1)
ret i32 undef
}
declare void @llvm.va_start(i8*) nounwind
declare i32 @foo(i32)
declare void @llvm.va_end(i8*) nounwind