diff options
| author | Paolo Bonzini <pbonzini@redhat.com> | 2023-12-28 13:05:24 +0100 |
|---|---|---|
| committer | Richard Henderson <richard.henderson@linaro.org> | 2024-01-11 08:46:35 +1100 |
| commit | afa37be4b4b0cd36150db7d62ab68f2673f7589a (patch) | |
| tree | e39c00f5e37b4a4c20f61706ccf684b21c31581a /tcg | |
| parent | 64708db302edfe57474239a51d4dad4466fac44a (diff) | |
tcg/i386: use 8-bit OR or XOR for unsigned 8-bit immediates
In the case where OR or XOR has an 8-bit immediate between 128 and 255,
we can operate on a low-byte register and shorten the output by two or
three bytes (two if a prefix byte is needed for REX.B).
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Message-Id: <20231228120524.70239-1-pbonzini@redhat.com>
[rth: Incorporate into switch.]
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Diffstat (limited to 'tcg')
| -rw-r--r-- | tcg/i386/tcg-target.c.inc | 11 |
1 files changed, 11 insertions, 0 deletions
diff --git a/tcg/i386/tcg-target.c.inc b/tcg/i386/tcg-target.c.inc index 29e80af78b..d268199fc1 100644 --- a/tcg/i386/tcg-target.c.inc +++ b/tcg/i386/tcg-target.c.inc @@ -244,6 +244,7 @@ static bool tcg_target_const_match(int64_t val, TCGType type, int ct, int vece) #define P_VEXL 0x80000 /* Set VEX.L = 1 */ #define P_EVEX 0x100000 /* Requires EVEX encoding */ +#define OPC_ARITH_EbIb (0x80) #define OPC_ARITH_EvIz (0x81) #define OPC_ARITH_EvIb (0x83) #define OPC_ARITH_GvEv (0x03) /* ... plus (ARITH_FOO << 3) */ @@ -1370,6 +1371,16 @@ static void tgen_arithi(TCGContext *s, int c, int r0, return; } break; + + case ARITH_OR: + case ARITH_XOR: + if (val >= 0x80 && val <= 0xff + && (r0 < 4 || TCG_TARGET_REG_BITS == 64)) { + tcg_out_modrm(s, OPC_ARITH_EbIb + P_REXB_RM, c, r0); + tcg_out8(s, val); + return; + } + break; } if (val == (int8_t)val) { |