b9c26a9cfe
Summary: The previous version relied on the standard calling convention using std::reverse() to try to force the AVR ABI. But this only works for simple cases, it fails for example with aggregate types. This patch rewrites the calling convention with custom C++ code, that implements the ABI defined in https://gcc.gnu.org/wiki/avr-gcc. To do that it adds a few 16-bit pseudo registers for unaligned argument passing, such as R24R23. For example this function: define void @fun({ i8, i16 } %a) will pass %a.0 in R22 and %a.1 in R24R23. There are no instructions that can use these pseudo registers, so a new register class, DREGSMOVW, is defined to make them apart. Also the ArgCC_AVR_BUILTIN_DIV is no longer necessary, as it is identical to the C++ behavior (actually the clobber list is more strict for __div* functions, but that is currently unimplemented). Reviewers: dylanmckay Subscribers: Gaelan, Sh4rK, indirect, jwagen, efriedma, dsprenkels, hiraditya, Jim, llvm-commits Tags: #llvm Differential Revision: https://reviews.llvm.org/D68524 Patch by Rodrigo Rivas Costa.
90 lines
2.5 KiB
LLVM
90 lines
2.5 KiB
LLVM
; RUN: llc < %s -march=avr | FileCheck %s
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declare void @ret_void_args_i8(i8 %a)
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declare void @ret_void_args_i8_i32(i8 %a, i32 %b)
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declare void @ret_void_args_i8_i8_i8_i8(i8 %a, i8 %b, i8 %c, i8 %d)
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declare void @ret_void_args_i32_i16_i8(i32 %a, i16 %b, i8 %c)
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declare void @ret_void_args_i64(i64 %a)
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declare void @ret_void_args_i64_i64(i64 %a, i64 %b)
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declare void @ret_void_args_i64_i64_i16(i64 %a, i64 %b, i16 %c)
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; CHECK-LABEL: call_void_args_i8
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define void @call_void_args_i8() {
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; CHECK: ldi r24, 64
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call void @ret_void_args_i8 (i8 64)
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ret void
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}
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; CHECK-LABEL: call_void_args_i8_i32
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define void @call_void_args_i8_i32() {
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; CHECK: ldi r20, 4
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; CHECK-NEXT: ldi r21, 3
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; CHECK-NEXT: ldi r22, 2
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; CHECK-NEXT: ldi r23, 1
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; CHECK-NEXT: ldi r24, 64
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call void @ret_void_args_i8_i32 (i8 64, i32 16909060)
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ret void
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}
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; CHECK-LABEL: call_void_args_i8_i8_i8_i8
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define void @call_void_args_i8_i8_i8_i8() {
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; CHECK: ldi r24, 1
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; CHECK-NEXT: ldi r22, 2
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; CHECK-NEXT: ldi r20, 3
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; CHECK-NEXT: ldi r18, 4
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call void @ret_void_args_i8_i8_i8_i8(i8 1, i8 2, i8 3, i8 4)
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ret void
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}
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; CHECK-LABEL: call_void_args_i32_i16_i8
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define void @call_void_args_i32_i16_i8() {
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; CHECK: ldi r22, 4
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; CHECK-NEXT: ldi r23, 3
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; CHECK-NEXT: ldi r24, 2
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; CHECK-NEXT: ldi r25, 1
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; CHECK-NEXT: ldi r20, 1
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; CHECK-NEXT: ldi r21, 4
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; CHECK-NEXT: ldi r18, 64
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call void @ret_void_args_i32_i16_i8(i32 16909060, i16 1025, i8 64)
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ret void
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}
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; CHECK-LABEL: call_void_args_i64
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define void @call_void_args_i64() {
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; CHECK: ldi r18, 8
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; CHECK-NEXT: ldi r19, 7
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; CHECK-NEXT: ldi r20, 6
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; CHECK-NEXT: ldi r21, 5
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; CHECK-NEXT: ldi r22, 4
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; CHECK-NEXT: ldi r23, 3
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; CHECK-NEXT: ldi r24, 2
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; CHECK-NEXT: ldi r25, 1
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call void @ret_void_args_i64(i64 72623859790382856)
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ret void
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}
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; CHECK-LABEL: call_void_args_i64_i64
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define void @call_void_args_i64_i64() {
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; CHECK: ldi r18, 8
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; CHECK-NEXT: ldi r19, 7
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; CHECK-NEXT: ldi r20, 6
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; CHECK-NEXT: ldi r21, 5
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; CHECK-NEXT: ldi r22, 4
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; CHECK-NEXT: ldi r23, 3
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; CHECK-NEXT: ldi r24, 2
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; CHECK-NEXT: ldi r25, 1
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; the second arg is in r10:r17, but unordered
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; CHECK: r17,
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; CHECK: r10,
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call void @ret_void_args_i64_i64(i64 72623859790382856, i64 651345242494996224)
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ret void
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}
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; CHECK-LABEL: call_void_args_i64_i64_i16
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define void @call_void_args_i64_i64_i16() {
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; CHECK: r8,
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; CHECK: r9,
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call void @ret_void_args_i64_i64_i16(i64 72623859790382856, i64 651345242494996224, i16 5655)
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ret void
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}
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