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tcg/optimize: improve known-zero bits for 32-bit ops 

The shl_i32 op might set some bits of the unused 32 high bits of the
mask. Fix that by clearing the unused 32 high bits for all 32-bit ops
except load/store which operate on tl values.

Reviewed-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Aurelien Jarno <aurelien@aurel32.net>
Signed-off-by: Richard Henderson <rth@twiddle.net>
This commit is contained in:
Aurelien Jarno 2013-09-03 08:27:38 +02:00 committed by Richard Henderson
parent 3031244b01
commit f096dc9618
1 changed files with 6 additions and 0 deletions
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6
tcg/optimize.c
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@ -783,6 +783,12 @@ static TCGArg *tcg_constant_folding(TCGContext *s, uint16_t *tcg_opc_ptr,
break;
}
/* 32-bit ops (non 64-bit ops and non load/store ops) generate 32-bit
results */
if (!(tcg_op_defs[op].flags & (TCG_OPF_CALL_CLOBBER | TCG_OPF_64BIT))) {
mask &= 0xffffffffu;
}
if (mask == 0) {
assert(def->nb_oargs == 1);
s->gen_opc_buf[op_index] = op_to_movi(op);