https://gcc.gnu.org/g:1385e403f29fc65719c022a9e58f01a4876750f5
commit r17-1261-g1385e403f29fc65719c022a9e58f01a4876750f5 Author: Pan Li <[email protected]> Date: Mon May 18 17:43:19 2026 +0800 Match: Support unsigned scalar SAT_MUL form 11 This patch would like to try to match the the unsigned SAT_MUL form 11, aka below #define DEF_SAT_U_MUL_FMT_11(NT, WT) \ NT __attribute__((noinline)) \ sat_u_mul_##NT##_from_##WT##_fmt_11 (NT a, NT b) \ { \ WT x = (WT)a * (WT)b; \ NT max = -1; \ bool overflow_p = x >= (WT)(max); \ return -(NT)(overflow_p) | (NT)x; \ } while WT is uint128_t, uint64_t, uint32_t and uint16_t, and NT is uint64_t, uint32_t, uint16_t or uint8_t. gcc/ChangeLog: * match-sat-alu.pd: Add pattern for unsigned scalar SAT_MUL form 11. Signed-off-by: Pan Li <[email protected]> Diff: --- gcc/match-sat-alu.pd | 11 ++++++++--- 1 file changed, 8 insertions(+), 3 deletions(-) diff --git a/gcc/match-sat-alu.pd b/gcc/match-sat-alu.pd index 483c37b6d9f6..6145a0c99484 100644 --- a/gcc/match-sat-alu.pd +++ b/gcc/match-sat-alu.pd @@ -548,7 +548,7 @@ along with GCC; see the file COPYING3. If not see /* SAT_U_MUL (X, Y) = { WT x = (WT)a * (WT)b; NT max = -1; - bool overflow_p = x > (WT)max; + bool overflow_p = x > (WT)max || x > (WT)(max - 1); return -(NT)(overflow_p) | (NT)x; } while WT is uint128_t, uint64_t, uint32_t, uint16_t, and T is uint64_t, uint32_t, uint16_t, uint8_t. */ @@ -560,7 +560,12 @@ along with GCC; see the file COPYING3. If not see unsigned prec = TYPE_PRECISION (type); unsigned widen_prec = TYPE_PRECISION (TREE_TYPE (@3)); wide_int max = wi::mask (prec, false, widen_prec); - bool c2_is_max_p = wi::eq_p (wi::to_wide (@2), max); + + wide_int c2 = wi::to_wide (@2); + bool c2_is_max_p = wi::eq_p (c2, max); + + wide_int c2_plus_one = wi::add (c2, wi::uhwi (1, widen_prec)); + bool c2_plus_one_is_max_p = wi::eq_p (c2_plus_one, max); } - (if (c2_is_max_p))))) + (if (c2_is_max_p || c2_plus_one_is_max_p))))) )
