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authorAurelien Jarno <aurelien@aurel32.net>2012-09-06 16:47:14 +0200
committerAurelien Jarno <aurelien@aurel32.net>2012-09-11 18:05:58 +0200
commit01ee5282ea955dee4e189b34ef888be6f36d9861 (patch)
tree10f6059b90f5a264fba1cf04ef0e81c929588b63 /tcg
parent61251c0c790d0a63468c8e3eb2767c1f4bf3654a (diff)
tcg/optimize: simplify shift/rot r, 0, a => movi r, 0 cases
shift/rot r, 0, a is equivalent to movi r, 0. Reviewed-by: Richard Henderson <rth@twiddle.net> Signed-off-by: Aurelien Jarno <aurelien@aurel32.net>
Diffstat (limited to 'tcg')
-rw-r--r--tcg/optimize.c20
1 files changed, 20 insertions, 0 deletions
diff --git a/tcg/optimize.c b/tcg/optimize.c
index c12cb2bc4b..1698ba39b3 100644
--- a/tcg/optimize.c
+++ b/tcg/optimize.c
@@ -322,6 +322,26 @@ static TCGArg *tcg_constant_folding(TCGContext *s, uint16_t *tcg_opc_ptr,
break;
}
+ /* Simplify expressions for "shift/rot r, 0, a => movi r, 0" */
+ switch (op) {
+ CASE_OP_32_64(shl):
+ CASE_OP_32_64(shr):
+ CASE_OP_32_64(sar):
+ CASE_OP_32_64(rotl):
+ CASE_OP_32_64(rotr):
+ if (temps[args[1]].state == TCG_TEMP_CONST
+ && temps[args[1]].val == 0) {
+ gen_opc_buf[op_index] = op_to_movi(op);
+ tcg_opt_gen_movi(gen_args, args[0], 0, nb_temps, nb_globals);
+ args += 3;
+ gen_args += 2;
+ continue;
+ }
+ break;
+ default:
+ break;
+ }
+
/* Simplify expression for "op r, a, 0 => mov r, a" cases */
switch (op) {
CASE_OP_32_64(add):