Cc: Blue Swirl <[email protected]>
Signed-off-by: Richard Henderson <[email protected]>
---
V2 properly does a reset_temp on the output of the neg.
This was the cause of the sparc32 boot problem.
r~
---
tcg/optimize.c | 34 +++++++++++++++++++++++++++++++++-
1 file changed, 33 insertions(+), 1 deletion(-)
diff --git a/tcg/optimize.c b/tcg/optimize.c
index bc6e5c1..1b6644c 100644
--- a/tcg/optimize.c
+++ b/tcg/optimize.c
@@ -576,7 +576,8 @@ static TCGArg *tcg_constant_folding(TCGContext *s, uint16_t
*tcg_opc_ptr,
break;
}
- /* Simplify expressions for "shift/rot r, 0, a => movi r, 0" */
+ /* Simplify expressions for "shift/rot r, 0, a => movi r, 0",
+ and "sub r, 0, a => neg r, a" case. */
switch (op) {
CASE_OP_32_64(shl):
CASE_OP_32_64(shr):
@@ -592,6 +593,37 @@ static TCGArg *tcg_constant_folding(TCGContext *s,
uint16_t *tcg_opc_ptr,
continue;
}
break;
+ CASE_OP_32_64(sub):
+ {
+ TCGOpcode neg_op;
+ bool have_neg;
+
+ if (temps[args[2]].state == TCG_TEMP_CONST) {
+ /* Proceed with possible constant folding. */
+ break;
+ }
+ if (op == INDEX_op_sub_i32) {
+ neg_op = INDEX_op_neg_i32;
+ have_neg = TCG_TARGET_HAS_neg_i32;
+ } else {
+ neg_op = INDEX_op_neg_i64;
+ have_neg = TCG_TARGET_HAS_neg_i64;
+ }
+ if (!have_neg) {
+ break;
+ }
+ if (temps[args[1]].state == TCG_TEMP_CONST
+ && temps[args[1]].val == 0) {
+ s->gen_opc_buf[op_index] = neg_op;
+ reset_temp(args[0]);
+ gen_args[0] = args[0];
+ gen_args[1] = args[2];
+ args += 3;
+ gen_args += 2;
+ continue;
+ }
+ }
+ break;
default:
break;
}
--
1.8.1.4
