llvm/test/CodeGen/X86/dynamic-allocas-VLAs.ll
Chad Rosier 1243922fc1 Remove the X86 Maximal Stack Alignment Check pass as it is no longer necessary.
This pass was conservative in that it always reserved the FP to enable dynamic
stack realignment, which allowed the RA to use aligned spills for vector
registers.  This happens even when spills were not necessary.  The RA has 
since been improved to use unaligned spills when necessary.

The new behavior is to realign the stack if the frame pointer was already
reserved for some other reason, but don't reserve the frame pointer just
because a function contains vector virtual registers.

Part of rdar://12719844

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@168627 91177308-0d34-0410-b5e6-96231b3b80d8
2012-11-26 22:55:05 +00:00

232 lines
5.8 KiB
LLVM

; RUN: llc < %s -mcpu=generic -march=x86-64 -mattr=+avx -mtriple=i686-apple-darwin10 | FileCheck %s
; RUN: llc < %s -mcpu=generic -force-align-stack -stack-alignment=32 -march=x86-64 -mattr=+avx -mtriple=i686-apple-darwin10 | FileCheck %s -check-prefix=FORCE-ALIGN
; rdar://11496434
; no VLAs or dynamic alignment
define i32 @t1() nounwind uwtable ssp {
entry:
%a = alloca i32, align 4
call void @t1_helper(i32* %a) nounwind
%0 = load i32* %a, align 4
%add = add nsw i32 %0, 13
ret i32 %add
; CHECK: _t1
; CHECK-NOT: andq $-{{[0-9]+}}, %rsp
; CHECK: leaq [[OFFSET:[0-9]*]](%rsp), %rdi
; CHECK: callq _t1_helper
; CHECK: movl [[OFFSET]](%rsp), %eax
; CHECK: addl $13, %eax
}
declare void @t1_helper(i32*)
; dynamic realignment
define i32 @t2() nounwind uwtable ssp {
entry:
%a = alloca i32, align 4
%v = alloca <8 x float>, align 32
call void @t2_helper(i32* %a, <8 x float>* %v) nounwind
%0 = load i32* %a, align 4
%add = add nsw i32 %0, 13
ret i32 %add
; CHECK: _t2
; CHECK: pushq %rbp
; CHECK: movq %rsp, %rbp
; CHECK: andq $-32, %rsp
; CHECK: subq ${{[0-9]+}}, %rsp
;
; CHECK: leaq {{[0-9]*}}(%rsp), %rdi
; CHECK: leaq {{[0-9]*}}(%rsp), %rsi
; CHECK: callq _t2_helper
;
; CHECK: movq %rbp, %rsp
; CHECK: popq %rbp
}
declare void @t2_helper(i32*, <8 x float>*)
; VLAs
define i32 @t3(i64 %sz) nounwind uwtable ssp {
entry:
%a = alloca i32, align 4
%vla = alloca i32, i64 %sz, align 16
call void @t3_helper(i32* %a, i32* %vla) nounwind
%0 = load i32* %a, align 4
%add = add nsw i32 %0, 13
ret i32 %add
; CHECK: _t3
; CHECK: pushq %rbp
; CHECK: movq %rsp, %rbp
; CHECK: pushq %rbx
; CHECK-NOT: andq $-{{[0-9]+}}, %rsp
; CHECK: subq ${{[0-9]+}}, %rsp
;
; CHECK: leaq -{{[0-9]+}}(%rbp), %rsp
; CHECK: popq %rbx
; CHECK: popq %rbp
}
declare void @t3_helper(i32*, i32*)
; VLAs + Dynamic realignment
define i32 @t4(i64 %sz) nounwind uwtable ssp {
entry:
%a = alloca i32, align 4
%v = alloca <8 x float>, align 32
%vla = alloca i32, i64 %sz, align 16
call void @t4_helper(i32* %a, i32* %vla, <8 x float>* %v) nounwind
%0 = load i32* %a, align 4
%add = add nsw i32 %0, 13
ret i32 %add
; CHECK: _t4
; CHECK: pushq %rbp
; CHECK: movq %rsp, %rbp
; CHECK: pushq %r14
; CHECK: pushq %rbx
; CHECK: andq $-32, %rsp
; CHECK: subq ${{[0-9]+}}, %rsp
; CHECK: movq %rsp, %rbx
;
; CHECK: leaq {{[0-9]*}}(%rbx), %rdi
; CHECK: leaq {{[0-9]*}}(%rbx), %rdx
; CHECK: callq _t4_helper
;
; CHECK: leaq -16(%rbp), %rsp
; CHECK: popq %rbx
; CHECK: popq %r14
; CHECK: popq %rbp
}
declare void @t4_helper(i32*, i32*, <8 x float>*)
; Spilling an AVX register shouldn't cause dynamic realignment
define i32 @t5(float* nocapture %f) nounwind uwtable ssp {
entry:
%a = alloca i32, align 4
%0 = bitcast float* %f to <8 x float>*
%1 = load <8 x float>* %0, align 32
call void @t5_helper1(i32* %a) nounwind
call void @t5_helper2(<8 x float> %1) nounwind
%2 = load i32* %a, align 4
%add = add nsw i32 %2, 13
ret i32 %add
; CHECK: _t5
; CHECK: subq ${{[0-9]+}}, %rsp
;
; CHECK: vmovaps (%rdi), [[AVXREG:%ymm[0-9]+]]
; CHECK: vmovups [[AVXREG]], (%rsp)
; CHECK: leaq {{[0-9]+}}(%rsp), %rdi
; CHECK: callq _t5_helper1
; CHECK: vmovups (%rsp), %ymm0
; CHECK: callq _t5_helper2
; CHECK: movl {{[0-9]+}}(%rsp), %eax
}
declare void @t5_helper1(i32*)
declare void @t5_helper2(<8 x float>)
; VLAs + Dynamic realignment + Spill
; FIXME: RA has already reserved RBX, so we can't do dynamic realignment.
define i32 @t6(i64 %sz, float* nocapture %f) nounwind uwtable ssp {
entry:
; CHECK: _t6
%a = alloca i32, align 4
%0 = bitcast float* %f to <8 x float>*
%1 = load <8 x float>* %0, align 32
%vla = alloca i32, i64 %sz, align 16
call void @t6_helper1(i32* %a, i32* %vla) nounwind
call void @t6_helper2(<8 x float> %1) nounwind
%2 = load i32* %a, align 4
%add = add nsw i32 %2, 13
ret i32 %add
}
declare void @t6_helper1(i32*, i32*)
declare void @t6_helper2(<8 x float>)
; VLAs + Dynamic realignment + byval
; The byval adjust the sp after the prolog, but if we're restoring the sp from
; the base pointer we use the original adjustment.
%struct.struct_t = type { [5 x i32] }
define void @t7(i32 %size, %struct.struct_t* byval align 8 %arg1) nounwind uwtable {
entry:
%x = alloca i32, align 32
store i32 0, i32* %x, align 32
%0 = zext i32 %size to i64
%vla = alloca i32, i64 %0, align 16
%1 = load i32* %x, align 32
call void @bar(i32 %1, i32* %vla, %struct.struct_t* byval align 8 %arg1)
ret void
; CHECK: _t7
; CHECK: pushq %rbp
; CHECK: movq %rsp, %rbp
; CHECK: pushq %rbx
; CHECK: andq $-32, %rsp
; CHECK: subq ${{[0-9]+}}, %rsp
; CHECK: movq %rsp, %rbx
; Stack adjustment for byval
; CHECK: subq {{.*}}, %rsp
; CHECK: callq _bar
; CHECK-NOT: addq {{.*}}, %rsp
; CHECK: leaq -8(%rbp), %rsp
; CHECK: popq %rbx
; CHECK: popq %rbp
}
declare i8* @llvm.stacksave() nounwind
declare void @bar(i32, i32*, %struct.struct_t* byval align 8)
declare void @llvm.stackrestore(i8*) nounwind
; Test when forcing stack alignment
define i32 @t8() nounwind uwtable {
entry:
%a = alloca i32, align 4
call void @t1_helper(i32* %a) nounwind
%0 = load i32* %a, align 4
%add = add nsw i32 %0, 13
ret i32 %add
; FORCE-ALIGN: _t8
; FORCE-ALIGN: movq %rsp, %rbp
; FORCE-ALIGN: andq $-32, %rsp
; FORCE-ALIGN-NEXT: subq $32, %rsp
; FORCE-ALIGN: movq %rbp, %rsp
; FORCE-ALIGN: popq %rbp
}
; VLAs
define i32 @t9(i64 %sz) nounwind uwtable {
entry:
%a = alloca i32, align 4
%vla = alloca i32, i64 %sz, align 16
call void @t3_helper(i32* %a, i32* %vla) nounwind
%0 = load i32* %a, align 4
%add = add nsw i32 %0, 13
ret i32 %add
; FORCE-ALIGN: _t9
; FORCE-ALIGN: pushq %rbp
; FORCE-ALIGN: movq %rsp, %rbp
; FORCE-ALIGN: pushq %rbx
; FORCE-ALIGN: andq $-32, %rsp
; FORCE-ALIGN: subq $32, %rsp
; FORCE-ALIGN: movq %rsp, %rbx
; FORCE-ALIGN: leaq -8(%rbp), %rsp
; FORCE-ALIGN: popq %rbx
; FORCE-ALIGN: popq %rbp
}