diff options
| author | Richard Henderson <rth@twiddle.net> | 2014-01-28 12:03:24 -0800 |
|---|---|---|
| committer | Richard Henderson <rth@twiddle.net> | 2014-02-17 10:12:29 -0600 |
| commit | 23ec69ed3759fe5d8374cb22795ade1305c331c4 (patch) | |
| tree | 1652dd79b9b51a35eda9211509e061124f152b2a | |
| parent | c8d70272535b84ccd3cd1a3dcad65aed34be6bb4 (diff) | |
tcg/optimize: Handle known-zeros masks for ANDC
Reviewed-by: Paolo Bonzini <pbonzini@redhat.com>
Reviewed-by: Aurelien Jarno <aurelien@aurel32.net>
Signed-off-by: Richard Henderson <rth@twiddle.net>
| -rw-r--r-- | tcg/optimize.c | 11 |
1 files changed, 11 insertions, 0 deletions
diff --git a/tcg/optimize.c b/tcg/optimize.c index 1b9fea5a3d..4bea8a56ef 100644 --- a/tcg/optimize.c +++ b/tcg/optimize.c @@ -727,6 +727,17 @@ static TCGArg *tcg_constant_folding(TCGContext *s, uint16_t *tcg_opc_ptr, mask = temps[args[1]].mask & mask; break; + CASE_OP_32_64(andc): + /* Known-zeros does not imply known-ones. Therefore unless + args[2] is constant, we can't infer anything from it. */ + if (temps[args[2]].state == TCG_TEMP_CONST) { + mask = ~temps[args[2]].mask; + goto and_const; + } + /* But we certainly know nothing outside args[1] may be set. */ + mask = temps[args[1]].mask; + break; + case INDEX_op_sar_i32: if (temps[args[2]].state == TCG_TEMP_CONST) { mask = (int32_t)temps[args[1]].mask >> temps[args[2]].val; |