Commit f096dc96 authored Sep 03, 2013 by Aurelien Jarno Committed by Richard Henderson Feb 17, 2014

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>

parent 3031244b

tcg/optimize.c

+6 −0

Original line number	Diff line number	Diff line
		@@ -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);