[binutils-gdb] RISC-V: reduce redundancy in sign/zero extension macro insn handling

[binutils-gdb] RISC-V: reduce redundancy in sign/zero extension macro insn handling

[Jan Beulich]

https://sourceware.org/git/gitweb.cgi?p=binutils-gdb.git;h=eb5e952f95423bc6ae18457ccc359c8b6c0fa387

commit eb5e952f95423bc6ae18457ccc359c8b6c0fa387
Author: Jan Beulich <jbeulich@suse.com>
Date:   Fri Nov 24 09:53:55 2023 +0100

    RISC-V: reduce redundancy in sign/zero extension macro insn handling
    
    Fold M_{S,Z}EXTH, deriving signed-ness from the incoming mnemonic. Fold
    riscv_ext()'s calls md_assemblef(), the first of which were entirely
    identical, while the other pair differed in just a single character.
    
    Acked-by: Palmer Dabbelt <palmer@rivosinc.com>

Diff:
---
 gas/config/tc-riscv.c  | 21 +++++----------------
 include/opcode/riscv.h |  3 +--
 opcodes/riscv-opc.c    |  4 ++--
 3 files changed, 8 insertions(+), 20 deletions(-)

diff --git a/gas/config/tc-riscv.c b/gas/config/tc-riscv.c
index 3222bd1aec7..04738d5e00c 100644
--- a/gas/config/tc-riscv.c
+++ b/gas/config/tc-riscv.c
@@ -1960,16 +1960,9 @@ load_const (int reg, expressionS *ep)
 static void
 riscv_ext (int destreg, int srcreg, unsigned shift, bool sign)
 {
-  if (sign)
-    {
-      md_assemblef ("slli x%d, x%d, 0x%x", destreg, srcreg, shift);
-      md_assemblef ("srai x%d, x%d, 0x%x", destreg, destreg, shift);
-    }
-  else
-    {
-      md_assemblef ("slli x%d, x%d, 0x%x", destreg, srcreg, shift);
-      md_assemblef ("srli x%d, x%d, 0x%x", destreg, destreg, shift);
-    }
+  md_assemblef ("slli x%d, x%d, %#x", destreg, srcreg, shift);
+  md_assemblef ("sr%ci x%d, x%d, %#x",
+		sign ? 'a' : 'l', destreg, destreg, shift);
 }
 
 /* Expand RISC-V Vector macros into one or more instructions.  */
@@ -2093,8 +2086,8 @@ macro (struct riscv_cl_insn *ip, expressionS *imm_expr,
       riscv_call (rd, rs1, imm_expr, *imm_reloc);
       break;
 
-    case M_ZEXTH:
-      riscv_ext (rd, rs1, xlen - 16, false);
+    case M_EXTH:
+      riscv_ext (rd, rs1, xlen - 16, *ip->insn_mo->name == 's');
       break;
 
     case M_ZEXTW:
@@ -2105,10 +2098,6 @@ macro (struct riscv_cl_insn *ip, expressionS *imm_expr,
       riscv_ext (rd, rs1, xlen - 8, true);
       break;
 
-    case M_SEXTH:
-      riscv_ext (rd, rs1, xlen - 16, true);
-      break;
-
     case M_VMSGE:
       vector_macro (ip);
       break;
diff --git a/include/opcode/riscv.h b/include/opcode/riscv.h
index 3099c9e256c..25486869606 100644
--- a/include/opcode/riscv.h
+++ b/include/opcode/riscv.h
@@ -558,10 +558,9 @@ enum
   M_CALL,
   M_J,
   M_LI,
-  M_ZEXTH,
+  M_EXTH,
   M_ZEXTW,
   M_SEXTB,
-  M_SEXTH,
   M_VMSGE,
   M_NUM_MACROS
 };
diff --git a/opcodes/riscv-opc.c b/opcodes/riscv-opc.c
index 39196e7f2f2..c9ba4c99284 100644
--- a/opcodes/riscv-opc.c
+++ b/opcodes/riscv-opc.c
@@ -1044,11 +1044,11 @@ const struct riscv_opcode riscv_opcodes[] =
 {"sext.b",     0, INSN_CLASS_I,         "d,s",   0, (int) M_SEXTB, NULL, INSN_MACRO },
 {"sext.h",     0, INSN_CLASS_ZCB_AND_ZBB,  "Cs,Cw", MATCH_C_SEXT_H, MASK_C_SEXT_H, match_opcode, INSN_ALIAS },
 {"sext.h",     0, INSN_CLASS_ZBB,  "d,s",   MATCH_SEXT_H, MASK_SEXT_H, match_opcode, 0 },
-{"sext.h",     0, INSN_CLASS_I,         "d,s",   0, (int) M_SEXTH, NULL, INSN_MACRO },
+{"sext.h",     0, INSN_CLASS_I,         "d,s",   0, (int) M_EXTH, NULL, INSN_MACRO },
 {"zext.h",     0, INSN_CLASS_ZCB_AND_ZBB,  "Cs,Cw", MATCH_C_ZEXT_H, MASK_C_ZEXT_H, match_opcode, INSN_ALIAS },
 {"zext.h",    32, INSN_CLASS_ZBB,  "d,s",   MATCH_PACK, MASK_PACK | MASK_RS2, match_opcode, 0 },
 {"zext.h",    64, INSN_CLASS_ZBB,  "d,s",   MATCH_PACKW, MASK_PACKW | MASK_RS2, match_opcode, 0 },
-{"zext.h",     0, INSN_CLASS_I,         "d,s",   0, (int) M_ZEXTH, NULL, INSN_MACRO },
+{"zext.h",     0, INSN_CLASS_I,         "d,s",   0, (int) M_EXTH, NULL, INSN_MACRO },
 {"orc.b",      0, INSN_CLASS_ZBB,  "d,s",   MATCH_GORCI | MATCH_SHAMT_ORC_B, MASK_GORCI | MASK_SHAMT, match_opcode, 0 },
 {"clzw",      64, INSN_CLASS_ZBB,  "d,s",   MATCH_CLZW, MASK_CLZW, match_opcode, 0 },
 {"ctzw",      64, INSN_CLASS_ZBB,  "d,s",   MATCH_CTZW, MASK_CTZW, match_opcode, 0 },