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https://github.com/c64scene-ar/llvm-6502.git
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52f83a9ab3
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
32 lines
1.1 KiB
LLVM
32 lines
1.1 KiB
LLVM
; RUN: llc < %s -mtriple=arm-nacl-gnueabi | FileCheck %s
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declare void @llvm.va_start(i8*)
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declare void @external_func(i8*)
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@va_list = external global i8*
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; On ARM, varargs arguments are passed in r0-r3 with the rest on the
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; stack. A varargs function must therefore spill rN-r3 just below the
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; function's initial stack pointer.
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;
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; This test checks for a bug in which a gap was left between the spill
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; area and varargs arguments on the stack when using 16 byte stack
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; alignment.
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define void @varargs_func(i32 %arg1, ...) {
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call void @llvm.va_start(i8* bitcast (i8** @va_list to i8*))
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call void @external_func(i8* bitcast (i8** @va_list to i8*))
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ret void
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}
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; CHECK-LABEL: varargs_func:
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; Reserve space for the varargs save area. This currently reserves
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; more than enough (16 bytes rather than the 12 bytes needed).
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; CHECK: sub sp, sp, #12
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; CHECK: push {r11, lr}
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; Align the stack pointer to a multiple of 16.
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; CHECK: sub sp, sp, #12
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; Calculate the address of the varargs save area and save varargs
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; arguments into it.
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; CHECK-NEXT: add r0, sp, #20
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; CHECK-NEXT: stm r0, {r1, r2, r3}
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