[1/2] Use 32/64_PCREL to replace a pair of ADD32/64 and SUB32/64.

Message ID 20230901030901.2519730-1-cailulu@loongson.cn
State Unresolved
Headers
Series [1/2] Use 32/64_PCREL to replace a pair of ADD32/64 and SUB32/64. |

Checks

Context Check Description
snail/binutils-gdb-check warning Git am fail log

Commit Message

Lulu Cai Sept. 1, 2023, 3:09 a.m. UTC
  Subtraction for labels that require static relocation
usually generates ADD32/64 and SUB32/64.

If subsy of BFD_RELOC_32/64 and PC in same segment,
and disable relax or PC at start of subsy or enable
relax but not in SEC_CODE, we generate 32/64_PCREL
to replace a pair of ADD32/64 and SUB32/64.
---
 gas/config/tc-loongarch.c | 22 ++++++++++++----------
 gas/config/tc-loongarch.h | 12 ++++++++++--
 2 files changed, 22 insertions(+), 12 deletions(-)
  

Patch

diff --git a/gas/config/tc-loongarch.c b/gas/config/tc-loongarch.c
index 2e8a259d147..57faffeb14d 100644
--- a/gas/config/tc-loongarch.c
+++ b/gas/config/tc-loongarch.c
@@ -1195,7 +1195,6 @@  md_apply_fix (fixS *fixP, valueT *valP, segT seg ATTRIBUTE_UNUSED)
   static int64_t stack_top;
   static int last_reloc_is_sop_push_pcrel_1 = 0;
   int last_reloc_is_sop_push_pcrel = last_reloc_is_sop_push_pcrel_1;
-  segT sub_segment;
   last_reloc_is_sop_push_pcrel_1 = 0;
 
   char *buf = fixP->fx_frag->fr_literal + fixP->fx_where;
@@ -1273,16 +1272,19 @@  md_apply_fix (fixS *fixP, valueT *valP, segT seg ATTRIBUTE_UNUSED)
        (use md_number_to_chars (buf, 0, fixP->fx_size)).  */
     case BFD_RELOC_64:
     case BFD_RELOC_32:
-      if (fixP->fx_r_type == BFD_RELOC_32
-	  && fixP->fx_addsy && fixP->fx_subsy
-	  && (sub_segment = S_GET_SEGMENT (fixP->fx_subsy))
-	  && strcmp (sub_segment->name, ".eh_frame") == 0
-	  && S_GET_VALUE (fixP->fx_subsy)
-	  == fixP->fx_frag->fr_address + fixP->fx_where)
+      if (fixP->fx_pcrel)
 	{
-	  fixP->fx_r_type = BFD_RELOC_LARCH_32_PCREL;
-	  fixP->fx_subsy = NULL;
-	  break;
+	  switch (fixP->fx_r_type)
+	    {
+	    case BFD_RELOC_64:
+	      fixP->fx_r_type = BFD_RELOC_LARCH_64_PCREL;
+	      break;
+	    case BFD_RELOC_32:
+	      fixP->fx_r_type = BFD_RELOC_LARCH_32_PCREL;
+	      break;
+	    default:
+	      break;
+	    }
 	}
 
       if (fixP->fx_addsy && fixP->fx_subsy)
diff --git a/gas/config/tc-loongarch.h b/gas/config/tc-loongarch.h
index a9f2a0a17cc..d353f18d0d2 100644
--- a/gas/config/tc-loongarch.h
+++ b/gas/config/tc-loongarch.h
@@ -71,8 +71,16 @@  extern bool loongarch_frag_align_code (int);
    relaxation, so do not resolve such expressions in the assembler.  */
 #define md_allow_local_subtract(l,r,s) 0
 
-/* Values passed to md_apply_fix don't include symbol values.  */
-#define TC_FORCE_RELOCATION_SUB_LOCAL(FIX, SEG) 1
+/* If subsy of BFD_RELOC32/64 and PC in same segment, and without relax
+   or PC at start of subsy or with relax but sub_symbol_segment not in
+   SEC_CODE, we generate 32/64_PCREL.  */
+#define TC_FORCE_RELOCATION_SUB_LOCAL(FIX, SEG) \
+  (!((BFD_RELOC_32 || BFD_RELOC_64) \
+     &&(!LARCH_opts.relax \
+       || S_GET_VALUE (FIX->fx_subsy) \
+	  == FIX->fx_frag->fr_address + FIX->fx_where \
+       || (LARCH_opts.relax \
+	  && ((S_GET_SEGMENT (FIX->fx_subsy)->flags & SEC_CODE) == 0)))))
 
 #define TC_VALIDATE_FIX_SUB(FIX, SEG) 1
 #define DIFF_EXPR_OK 1