llvm-6502/test/CodeGen/ARM/2012-10-04-AAPCS-byval-align8.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

66 lines
2.1 KiB
LLVM

; RUN: llc < %s -mtriple=armv7-none-linux-gnueabi | FileCheck %s
; Test that we correctly use registers and align elements when using va_arg
%struct_t = type { double, double, double }
@static_val = constant %struct_t { double 1.0, double 2.0, double 3.0 }
declare void @llvm.va_start(i8*) nounwind
declare void @llvm.va_end(i8*) nounwind
; CHECK-LABEL: test_byval_8_bytes_alignment:
define void @test_byval_8_bytes_alignment(i32 %i, ...) {
entry:
; CHECK: sub sp, sp, #12
; CHECK: sub sp, sp, #4
; CHECK: stmib sp, {r1, r2, r3}
%g = alloca i8*
%g1 = bitcast i8** %g to i8*
call void @llvm.va_start(i8* %g1)
; CHECK: add [[REG:(r[0-9]+)|(lr)]], {{(r[0-9]+)|(lr)}}, #7
; CHECK: bfc [[REG]], #0, #3
%0 = va_arg i8** %g, double
call void @llvm.va_end(i8* %g1)
ret void
}
; CHECK-LABEL: main:
; CHECK: movw [[BASE:r[0-9]+]], :lower16:static_val
; CHECK: movt [[BASE]], :upper16:static_val
; ldm is not formed when the coalescer failed to coalesce everything.
; CHECK: ldrd r2, [[TMP:r[0-9]+]], {{\[}}[[BASE]]{{\]}}
; CHECK: movw r0, #555
define i32 @main() {
entry:
call void (i32, ...)* @test_byval_8_bytes_alignment(i32 555, %struct_t* byval @static_val)
ret i32 0
}
declare void @f(double);
; CHECK-LABEL: test_byval_8_bytes_alignment_fixed_arg:
; CHECK-NOT: str r1
; CHECK: str r3, [sp, #12]
; CHECK: str r2, [sp, #8]
; CHECK-NOT: str r1
define void @test_byval_8_bytes_alignment_fixed_arg(i32 %n1, %struct_t* byval %val) nounwind {
entry:
%a = getelementptr inbounds %struct_t, %struct_t* %val, i32 0, i32 0
%0 = load double, double* %a
call void (double)* @f(double %0)
ret void
}
; CHECK-LABEL: main_fixed_arg:
; CHECK: movw [[BASE:r[0-9]+]], :lower16:static_val
; CHECK: movt [[BASE]], :upper16:static_val
; ldm is not formed when the coalescer failed to coalesce everything.
; CHECK: ldrd r2, [[TMP:r[0-9]+]], {{\[}}[[BASE]]{{\]}}
; CHECK: movw r0, #555
define i32 @main_fixed_arg() {
entry:
call void (i32, %struct_t*)* @test_byval_8_bytes_alignment_fixed_arg(i32 555, %struct_t* byval @static_val)
ret i32 0
}