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[compiler-rt][builtins] Fix wrong ABI of AVR __mulqi3 & __mulhi3

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Reviewed By: aykevl, dylanmckay

Differential Revision: https://reviews.llvm.org/D125077
This commit is contained in:
Ben Shi
2022-05-06 07:21:19 +00:00
parent 5a08e81779
commit 3902ebdd57
4 changed files with 71 additions and 34 deletions
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6
clang/lib/Basic/Targets/AVR.cpp
View File

@@ -380,13 +380,13 @@ void AVRTargetInfo::getTargetDefines(const LangOptions &Opts,
Builder.defineMacro("__AVR__");
Builder.defineMacro("__ELF__");
if (ABI == "avrtiny")
Builder.defineMacro("__AVR_TINY__", "1");
if (!this->CPU.empty()) {
auto It = llvm::find_if(
AVRMcus, [&](const MCUInfo &Info) { return Info.Name == this->CPU; });
if (It->IsTiny)
Builder.defineMacro("__AVR_TINY__", "1");
if (It != std::end(AVRMcus)) {
Builder.defineMacro(It->DefineName);
if (It->NumFlashBanks >= 1)

2
clang/test/Preprocessor/avr-common.c
View File

@@ -1,5 +1,7 @@
// RUN: %clang_cc1 -E -dM -triple avr-unknown-unknown -target-cpu attiny13 /dev/null | FileCheck -match-full-lines --check-prefixes=CHECK,AVR %s
// RUN: %clang_cc1 -E -dM -triple avr-unknown-unknown -target-cpu avr25 /dev/null | FileCheck -match-full-lines --check-prefixes=CHECK,AVR %s
// RUN: %clang_cc1 -E -dM -triple avr-unknown-unknown -target-cpu attiny4 /dev/null | FileCheck -match-full-lines --check-prefixes=CHECK,TINY %s
// RUN: %clang_cc1 -E -dM -triple avr-unknown-unknown -target-cpu avrtiny /dev/null | FileCheck -match-full-lines --check-prefixes=CHECK,TINY %s
// CHECK: #define AVR 1
// CHECK: #define __AVR 1

55
compiler-rt/lib/builtins/avr/mulhi3.S
View File

@@ -19,40 +19,53 @@
// return S;
// }
//
// __mulhi3 has special ABI, as the implementation of libgcc, R25:R24 is used
// to return result, while Rtmp/R21/R22/R23 are clobbered.
//
//===----------------------------------------------------------------------===//
.text
.align 2
#ifdef __AVR_TINY__
.set __tmp_reg__, 16
.set __zero_reg__, 17
#else
.set __tmp_reg__, 0
.set __zero_reg__, 1
#endif
.globl __mulhi3
.type __mulhi3, @function
__mulhi3:
eor r28, r28
eor r20, r20
eor r21, r21 ; Initialize the result to 0: `S = 0;`.
; Use Rzero:Rtmp to store the result.
clr __tmp_reg__
clr __zero_reg__ ; S = 0;
__mulhi3_loop:
cp r24, r28
cpc r25, r28 ; `while (A != 0) { ... }`
breq __mulhi3_end ; End the loop if A is 0.
clr r21
cp r24, r21
cpc r25, r21
breq __mulhi3_end ; while (A != 0) {
mov r29, r24
andi r29, 1 ; `if (A & 1) { ... }`
breq __mulhi3_loop_a ; Omit the accumulation (`S += B;`) if A's LSB is 0.
add r20, r22
adc r21, r23 ; Do the accumulation: `S += B;`.
mov r21, r24
andi r21, 1
breq __mulhi3_loop_a ; if (A & 1)
add __tmp_reg__, r22
adc __zero_reg__, r23 ; S += B;
__mulhi3_loop_a:
lsr r25
ror r24 ; `A = ((unsigned int) A) >> 1;`.
lsl r22
rol r23 ; `B <<= 1;`
rjmp __mulhi3_loop
lsr r25
ror r24 ; A = ((unsigned int) A) >> 1;
lsl r22
rol r23 ; B <<= 1;
rjmp __mulhi3_loop ; }
__mulhi3_end:
mov r24, r20
mov r25, r21
ret
; Return the result via R25:R24.
mov r24, __tmp_reg__
mov r25, __zero_reg__
; Restore __zero_reg__ to 0.
clr __zero_reg__
ret ; return S;

42
compiler-rt/lib/builtins/avr/mulqi3.S
View File

@@ -8,24 +8,46 @@
//
// The corresponding C code is something like:
//
// int __mulqi3(char A, char B) {
// return __mulhi3((int) A, (int) B);
// char __mulqi3(char A, char B) {
// int S = 0;
// while (A != 0) {
// if (A & 1)
// S += B;
// B <<= 1;
// A = ((unsigned char) A) >> 1;
// }
// return S;
// }
//
// __mulqi3 has special ABI, as the implementation of libgcc, the result is
// returned via R24, while Rtmp and R22 are clobbered.
//
//===----------------------------------------------------------------------===//
.text
.align 2
#ifdef __AVR_TINY__
.set __tmp_reg__, 16
#else
.set __tmp_reg__, 0
#endif
.globl __mulqi3
.type __mulqi3, @function
__mulqi3:
mov r25, r24
lsl r25
sbc r25, r25 ; Promote A from char to int: `(int) A`.
mov r23, r22
lsl r23
sbc r23, r23 ; Promote B from char to int: `(int) B`.
rcall __mulhi3 ; `__mulhi3((int) A, (int) B);`.
ret
clr __tmp_reg__ ; S = 0;
__mulqi3_loop:
cpi r24, 0
breq __mulqi3_end ; while (A != 0) {
sbrc r24, 0 ; if (A & 1)
add __tmp_reg__, r22 ; S += B;
add r22, r22 ; B <<= 1;
lsr r24 ; A = ((unsigned char) A) >> 1;
rjmp __mulqi3_loop ; }
__mulqi3_end:
mov r24, __tmp_reg__
ret ; return S;