x86: improve/shorten vector zeroing-idiom optimization conditional

- Drop the rounding type check: We're past template matching, and none
  of the involved insns support embedded rounding.
- Drop the extension opcode check: None of the involved opcodes have
  variants with it being other than None.
- Instead check opcode space, even if just to be on the safe side going
  forward.
- Reduce the number of comparisons by folding two groups.

diff --git a/gas/config/tc-i386.c b/gas/config/tc-i386.c
index 78dad4ebdf101070955543e99ce710bd98a15813..62d583be47ca29bf39d88ea10f1f47775fdb58bd 100644 (file)
--- a/gas/config/tc-i386.c
+++ b/gas/config/tc-i386.c
@@ -4329,24 +4329,19 @@ optimize_encoding (void)
           && !i.types[2].bitfield.xmmword
           && (i.tm.opcode_modifier.vex
               || ((!i.mask.reg || i.mask.zeroing)
-                  && i.rounding.type == rc_none
                   && is_evex_encoding (&i.tm)
                   && (i.vec_encoding != vex_encoding_evex
                       || cpu_arch_isa_flags.bitfield.cpuavx512vl
                       || i.tm.cpu_flags.bitfield.cpuavx512vl
                       || (i.tm.operand_types[2].bitfield.zmmword
                           && i.types[2].bitfield.ymmword))))
-          && ((i.tm.base_opcode == 0x55
-               || i.tm.base_opcode == 0x57
-               || i.tm.base_opcode == 0xdf
-               || i.tm.base_opcode == 0xef
-               || i.tm.base_opcode == 0xf8
-               || i.tm.base_opcode == 0xf9
-               || i.tm.base_opcode == 0xfa
-               || i.tm.base_opcode == 0xfb
-               || i.tm.base_opcode == 0x42
-               || i.tm.base_opcode == 0x47)
-              && i.tm.extension_opcode == None))
+          && i.tm.opcode_modifier.opcodespace == SPACE_0F
+          && ((i.tm.base_opcode | 2) == 0x57
+              || i.tm.base_opcode == 0xdf
+              || i.tm.base_opcode == 0xef
+              || (i.tm.base_opcode | 3) == 0xfb
+              || i.tm.base_opcode == 0x42
+              || i.tm.base_opcode == 0x47))
     {
       /* Optimize: -O1:
           VOP, one of vandnps, vandnpd, vxorps, vxorpd, vpsubb, vpsubd,