diff options
| author | Paolo Bonzini <pbonzini@redhat.com> | 2024-06-20 11:31:33 +0200 |
|---|---|---|
| committer | Paolo Bonzini <pbonzini@redhat.com> | 2024-10-31 18:28:33 +0100 |
| commit | 37df7c4d577124e01f087f598842b253aa2c9eca (patch) | |
| tree | e903506b7a1d7800983ffdc82fa30c2fd4d8c5f2 /target | |
| parent | ae14b33de8d329d5497db5446bdc0b0cb6ba756b (diff) | |
target/i386: optimize TEST+Jxx sequences
Mostly used for TEST+JG and TEST+JLE, but it is easy to cover
also JBE/JA and JL/JGE; shaves about 0.5% TCG ops.
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Diffstat (limited to 'target')
| -rw-r--r-- | target/i386/tcg/translate.c | 22 |
1 files changed, 22 insertions, 0 deletions
diff --git a/target/i386/tcg/translate.c b/target/i386/tcg/translate.c index 5e326ab1af..d3bbcf7317 100644 --- a/target/i386/tcg/translate.c +++ b/target/i386/tcg/translate.c @@ -1069,6 +1069,28 @@ static CCPrepare gen_prepare_cc(DisasContext *s, int b, TCGv reg) } break; + case CC_OP_LOGICB ... CC_OP_LOGICQ: + /* Mostly used for test+jump */ + size = s->cc_op - CC_OP_LOGICB; + switch (jcc_op) { + case JCC_BE: + /* CF = 0, becomes jz/je */ + jcc_op = JCC_Z; + goto slow_jcc; + case JCC_L: + /* OF = 0, becomes js/jns */ + jcc_op = JCC_S; + goto slow_jcc; + case JCC_LE: + /* SF or ZF, becomes signed <= 0 */ + tcg_gen_ext_tl(cpu_cc_dst, cpu_cc_dst, size | MO_SIGN); + cc = (CCPrepare) { .cond = TCG_COND_LE, .reg = cpu_cc_dst }; + break; + default: + goto slow_jcc; + } + break; + default: slow_jcc: /* This actually generates good code for JC, JZ and JS. */ |