This CL changes the function prologue and epilogue emitted on X86 when stack needs realignment.
It is intended to fix PR11468.
Old prologue and epilogue looked like this:
push %rbp
mov %rsp, %rbp
and $alignment, %rsp
push %r14
push %r15
...
pop %r15
pop %r14
mov %rbp, %rsp
pop %rbp
The problem was to reference the locations of callee-saved registers in exception handling:
locations of callee-saved had to be re-calculated regarding the stack alignment operation. It would
take some effort to implement this in LLVM, as currently MachineLocation can only have the form
"Register + Offset". Funciton prologue and epilogue are now changed to:
push %rbp
mov %rsp, %rbp
push %14
push %15
and $alignment, %rsp
...
lea -$size_of_saved_registers(%rbp), %rsp
pop %r15
pop %r14
pop %rbp
Reviewed by Chad Rosier.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@160248 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/test/CodeGen/X86/dynamic-allocas-VLAs.ll b/test/CodeGen/X86/dynamic-allocas-VLAs.ll
index c7970d4..54ae39b 100644
--- a/test/CodeGen/X86/dynamic-allocas-VLAs.ll
+++ b/test/CodeGen/X86/dynamic-allocas-VLAs.ll
@@ -85,20 +85,19 @@
; CHECK: _t4
; CHECK: pushq %rbp
; CHECK: movq %rsp, %rbp
-; CHECK: andq $-32, %rsp
; CHECK: pushq %r14
; CHECK: pushq %rbx
-; CHECK: subq $[[STACKADJ:[0-9]+]], %rsp
+; 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: addq $[[STACKADJ]], %rsp
+; CHECK: leaq -16(%rbp), %rsp
; CHECK: popq %rbx
; CHECK: popq %r14
-; CHECK: movq %rbp, %rsp
; CHECK: popq %rbp
}
@@ -176,19 +175,17 @@
; CHECK: _t7
; CHECK: pushq %rbp
; CHECK: movq %rsp, %rbp
-; CHECK: andq $-32, %rsp
; CHECK: pushq %rbx
-; CHECK: subq $[[ADJ:[0-9]+]], %rsp
+; 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: movq %rbx, %rsp
-; CHECK: addq $[[ADJ]], %rsp
+; CHECK: leaq -8(%rbp), %rsp
; CHECK: popq %rbx
-; CHECK: movq %rbp, %rsp
; CHECK: popq %rbp
}
@@ -229,14 +226,12 @@
; FORCE-ALIGN: _t9
; FORCE-ALIGN: pushq %rbp
; FORCE-ALIGN: movq %rsp, %rbp
-; FORCE-ALIGN: andq $-32, %rsp
; FORCE-ALIGN: pushq %rbx
-; FORCE-ALIGN: subq $24, %rsp
+; FORCE-ALIGN: andq $-32, %rsp
+; FORCE-ALIGN: subq $32, %rsp
; FORCE-ALIGN: movq %rsp, %rbx
-; FORCE-ALIGN: movq %rbx, %rsp
-; FORCE-ALIGN: addq $24, %rsp
+; FORCE-ALIGN: leaq -8(%rbp), %rsp
; FORCE-ALIGN: popq %rbx
-; FORCE-ALIGN: movq %rbp, %rsp
; FORCE-ALIGN: popq %rbp
}