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

[Fei Gao]

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.
---
 gcc/config/riscv/riscv.cc | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/gcc/config/riscv/riscv.cc b/gcc/config/riscv/riscv.cc
index 85db1e3c86b..469af02bdf7 100644
--- a/gcc/config/riscv/riscv.cc
+++ b/gcc/config/riscv/riscv.cc
@@ -5652,7 +5652,7 @@ riscv_expand_epilogue (int style)
                                           adjust));
          rtx dwarf = NULL_RTX;
          rtx cfa_adjust_rtx = gen_rtx_PLUS (Pmode, stack_pointer_rtx,
-                                            GEN_INT (step2));
+                                            GEN_INT (step2 + libcall_size));
 
          dwarf = alloc_reg_note (REG_CFA_DEF_CFA, cfa_adjust_rtx, dwarf);
          RTX_FRAME_RELATED_P (insn) = 1;
@@ -5689,7 +5689,7 @@ riscv_expand_epilogue (int style)
 
       rtx dwarf = NULL_RTX;
       rtx cfa_adjust_rtx = gen_rtx_PLUS (Pmode, stack_pointer_rtx,
-                                        const0_rtx);
+                                        GEN_INT (libcall_size ));
       dwarf = alloc_reg_note (REG_CFA_DEF_CFA, cfa_adjust_rtx, dwarf);
       RTX_FRAME_RELATED_P (insn) = 1;
 
-- 
2.17.1