Re: [PATCH 1/2] [RISC-V] fix cfi issue in save-restore.

[Jeff Law <jeffreyalaw@gmail.com>]

On 6/2/23 04:42, Fei Gao wrote:
> This patch fixes a cfi issue introduced by
> https://gcc.gnu.org/git/?p=gcc.git;a=commit;h=60524be1e3929d83e15fceac6e2aa053c8a6fb20
> 
> Test code:
> char my_getchar();
> float getf();
> int test_f0()
> {
>    int s0 = my_getchar();
>    float f0 = getf();
>    int b = my_getchar();
>    return f0+s0+b;
> }
> 
> cflags: -g -Os -march=rv32imafc -mabi=ilp32f -msave-restore -mcmodel=medlow
> 
> before patch:
> test_f0:
> ...
> 	.cfi_startproc
> 	call	t0,__riscv_save_1
> 	.cfi_offset 8, -8
> 	.cfi_offset 1, -4
> 	.cfi_def_cfa_offset 16
> ...
> 	addi	sp,sp,-16
> 	.cfi_def_cfa_offset 32
> 
> ...
> 
> 	addi	sp,sp,16
> 	.cfi_def_cfa_offset 0  // issue here
> ...
> 	tail	__riscv_restore_1
> 	.cfi_restore 8
> 	.cfi_restore 1
> 	.cfi_def_cfa_offset -16 // issue here
> 	.cfi_endproc
> 
> after patch:
> test_f0:
> ...
> 	.cfi_startproc
> 	call	t0,__riscv_save_1
> 	.cfi_offset 8, -8
> 	.cfi_offset 1, -4
> 	.cfi_def_cfa_offset 16
> ...
> 	addi	sp,sp,-16
> 	.cfi_def_cfa_offset 32
> 
> ...
> 
> 	addi	sp,sp,16
> 	.cfi_def_cfa_offset 16  // corrected here
> ...
> 	tail	__riscv_restore_1
> 	.cfi_restore 8
> 	.cfi_restore 1
> 	.cfi_def_cfa_offset 0 // corrected here
> 	.cfi_endproc
> 
> gcc/ChangeLog:
> 
>          * config/riscv/riscv.cc (riscv_expand_epilogue): fix cfi issue with correct offset.
I fixed a trivial whitespace problem, rewrapped the ChangeLog and pushed 
this patch to the trunk.  Please consider adding a testcase for this bug 
to the testsuite.

jeff