===================================================================
@@ -1043,13 +1043,19 @@
;; SImode unsigned integer comparisons
;; -------------------------------------------------------------------------
+;; Usually comparisons of 'unsigned int >= 0' are optimized away completely.
+;; However, especially when optimizations are off (e.g. -O0) such comparisons
+;; might remain and we have to handle them. If the '>= 0' case wasn't
+;; handled here, something else would just load a '0' into the second operand
+;; and do the comparison. We can do slightly better by just setting the
+;; T bit to '1'.
(define_insn_and_split "cmpgeusi_t"
[(set (reg:SI T_REG)
(geu:SI (match_operand:SI 0 "arith_reg_operand" "r")
- (match_operand:SI 1 "arith_reg_or_0_operand" "rN")))]
+ (match_operand:SI 1 "arith_reg_or_0_operand" "r")))]
"TARGET_SH1"
"cmp/hs %1,%0"
- "&& satisfies_constraint_Z (operands[0])"
+ "&& satisfies_constraint_Z (operands[1])"
[(set (reg:SI T_REG) (const_int 1))]
""
[(set_attr "type" "mt_group")])
Hello, This is the patch for this issue as mentioned in the PR. Tested on rev 190840 with make -k check RUNTESTFLAGS="--target_board=sh-sim \{-m2/-ml,-m2/-mb,-m2a/-mb,-m4/-ml,-m4/-mb,-m4a/-ml,-m4a/-mb}" and no new failures. OK? Cheers, Oleg ChangeLog: PR target/54418 * config/sh/sh.md (cmpgeusi_t): Remove N alternative. Check operands[1] in split condition instead of operands[0]. Add comments.