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tcg/i386: Use TEST r,r to test 8/16/32 bits

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Just like when testing against the sign bits, TEST r,r can be used when the
immediate is 0xff, 0xff00, 0xffff, 0xffffffff.

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
This commit is contained in:
Paolo Bonzini 2024-01-10 09:30:32 +11:00 committed by Richard Henderson
parent d3d1c30c63
commit be1335dba1
1 changed files with 17 additions and 0 deletions
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17
tcg/i386/tcg-target.c.inc
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@ -1501,6 +1501,10 @@ static int tcg_out_cmp(TCGContext *s, TCGCond cond, TCGArg arg1,
tcg_out_modrm(s, OPC_TESTB | P_REXB_R, arg1, arg1);
return js;
}
if (arg2 == 0xff) {
tcg_out_modrm(s, OPC_TESTB | P_REXB_R, arg1, arg1);
return jz;
}
tcg_out_modrm(s, OPC_GRP3_Eb | P_REXB_RM, EXT3_TESTi, arg1);
tcg_out8(s, arg2);
return jz;
@ -1511,11 +1515,24 @@ static int tcg_out_cmp(TCGContext *s, TCGCond cond, TCGArg arg1,
tcg_out_modrm(s, OPC_TESTB, arg1 + 4, arg1 + 4);
return js;
}
if (arg2 == 0xff00) {
tcg_out_modrm(s, OPC_TESTB, arg1 + 4, arg1 + 4);
return jz;
}
tcg_out_modrm(s, OPC_GRP3_Eb, EXT3_TESTi, arg1 + 4);
tcg_out8(s, arg2 >> 8);
return jz;
}
if (arg2 == 0xffff) {
tcg_out_modrm(s, OPC_TESTL | P_DATA16, arg1, arg1);
return jz;
}
if (arg2 == 0xffffffffu) {
tcg_out_modrm(s, OPC_TESTL, arg1, arg1);
return jz;
}
if (is_power_of_2(rexw ? arg2 : (uint32_t)arg2)) {
int jc = (cond == TCG_COND_TSTNE ? JCC_JB : JCC_JAE);
int sh = ctz64(arg2);