https://gcc.gnu.org/g:8a41790b7c3ddfbd0f15941a9fb4953cb0abe8d9
commit 8a41790b7c3ddfbd0f15941a9fb4953cb0abe8d9 Author: Jeff Law <[email protected]> Date: Mon Nov 3 12:46:23 2025 -0700 [PR rtl-optimization/122536] Fix guard against variable bit extracts in RTL simplifier While I haven't been able to reproduce the failure Sam reported, based on the RTL checking failure point and the code in question it was pretty clear the code that was supposed to guard against a variable bit extract was just checking the wrong argument to verify it was a constant integer -- it missed a level of XEXP object extraction. I passed this patch along to Sam and he verified it fixes his kernel build. I've bootstrapped and regression tested on x86_64. Pushing to the trunk. Pushing to the trunk. PR rtl-optimization/122536 gcc/ * simplify-rtx.cc (simplify_context::simplify_binary_operation_1): Fix guard against variable bit extracts in recent change. (cherry picked from commit 0f4afd8bb164054c227b2678169c0b098479a753) Diff: --- gcc/simplify-rtx.cc | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-) diff --git a/gcc/simplify-rtx.cc b/gcc/simplify-rtx.cc index 944725f648ba..1b32f0137568 100644 --- a/gcc/simplify-rtx.cc +++ b/gcc/simplify-rtx.cc @@ -3633,8 +3633,8 @@ simplify_context::simplify_binary_operation_1 (rtx_code code, && XEXP (op0, 1) == CONST1_RTX (mode) && XEXP (op1, 1) == CONST1_RTX (mode) /* Verify bit positions (for cases with variable bit position). */ - && CONST_INT_P (XEXP (op0, 1)) - && CONST_INT_P (XEXP (op1, 1))) + && CONST_INT_P (XEXP (XEXP (op0, 0), 1)) + && CONST_INT_P (XEXP (XEXP (op1, 0), 1))) { unsigned HOST_WIDE_INT bitpos1 = INTVAL (XEXP (XEXP (op0, 0), 1)); unsigned HOST_WIDE_INT bitpos2 = INTVAL (XEXP (XEXP (op1, 0), 1)); @@ -3665,7 +3665,7 @@ simplify_context::simplify_binary_operation_1 (rtx_code code, && XEXP (op0, 1) == CONST1_RTX (mode) && XEXP (op1, 1) == CONST0_RTX (mode) /* Verify bit position. */ - && CONST_INT_P (XEXP (op0, 1))) + && CONST_INT_P (XEXP (XEXP (op0, 0), 1))) { unsigned HOST_WIDE_INT bitpos1 = INTVAL (XEXP (XEXP (op0, 0), 1)); unsigned HOST_WIDE_INT mask
