[gcc(refs/vendors/riscv/heads/gcc-15-with-riscv-opts)] [PR rtl-optimization/122536] Fix guard against variable bit extracts in RTL simplifier

[Jeff Law]

https://gcc.gnu.org/g:e2215da742c8de84de0690749fb898b741a4a865

commit e2215da742c8de84de0690749fb898b741a4a865
Author: Jeff Law <jlaw@ventanamicro.com>
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 7220fc59eb7b..2f9a1d369dad 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