--- gcc/gimple-lower-bitint.cc.jj	2023-12-20 11:32:45.898425928 +0100
+++ gcc/gimple-lower-bitint.cc	2023-12-20 12:47:00.168727583 +0100
@@ -6060,6 +6060,26 @@ gimple_lower_bitint (void)
 			  || (bitint_precision_kind (TREE_TYPE (rhs1))
 			      < bitint_prec_large))
 			continue;
+		      if (is_gimple_assign (use_stmt))
+			switch (gimple_assign_rhs_code (use_stmt))
+			  {
+			  case MULT_EXPR:
+			  case TRUNC_DIV_EXPR:
+			  case TRUNC_MOD_EXPR:
+			  case FLOAT_EXPR:
+			    /* Uses which use handle_operand_addr can't
+			       deal with nested casts.  */
+			    if (TREE_CODE (rhs1) == SSA_NAME
+				&& gimple_assign_cast_p
+				     (SSA_NAME_DEF_STMT (rhs1))
+				&& has_single_use (rhs1)
+				&& (gimple_bb (SSA_NAME_DEF_STMT (rhs1))
+				    == gimple_bb (SSA_NAME_DEF_STMT (s))))
+			      goto force_name;
+			    break;
+			  default:
+			    break;
+			}
 		      if ((TYPE_PRECISION (TREE_TYPE (rhs1))
 			   >= TYPE_PRECISION (TREE_TYPE (s)))
 			  && mergeable_op (use_stmt))
@@ -6154,6 +6174,7 @@ gimple_lower_bitint (void)
 	      && (!SSA_NAME_VAR (s) || VAR_P (SSA_NAME_VAR (s))))
 	    continue;
 
+	force_name:
 	  if (!large_huge.m_names)
 	    large_huge.m_names = BITMAP_ALLOC (NULL);
 	  bitmap_set_bit (large_huge.m_names, SSA_NAME_VERSION (s));
--- gcc/testsuite/gcc.dg/bitint-56.c.jj	2023-12-20 12:41:28.208398219 +0100
+++ gcc/testsuite/gcc.dg/bitint-56.c	2023-12-20 12:38:08.548204489 +0100
@@ -0,0 +1,129 @@
+/* PR tree-optimization/112941 */
+/* { dg-do compile { target bitint } } */
+/* { dg-options "-std=c23 -O2" } */
+
+#if __BITINT_MAXWIDTH__ >= 4096
+void
+f1 (_BitInt(4096) *p, int r, _BitInt(115) s, _BitInt(128) t, _BitInt(231) u)
+{
+  p[0] *= (unsigned _BitInt(2048)) r;
+  p[1] *= (unsigned _BitInt(2048)) s;
+  p[2] *= (unsigned _BitInt(2048)) t;
+  p[3] *= (unsigned _BitInt(2048)) u;
+}
+
+void
+f2 (_BitInt(4094) *p, int r, _BitInt(115) s, _BitInt(128) t, _BitInt(231) u)
+{
+  p[0] /= (unsigned _BitInt(2048)) r;
+  p[1] /= (unsigned _BitInt(2048)) s;
+  p[2] /= (unsigned _BitInt(2048)) t;
+  p[3] /= (unsigned _BitInt(2048)) u;
+}
+
+void
+f3 (_BitInt(4096) *p, int r, _BitInt(115) s, _BitInt(128) t, _BitInt(231) u)
+{
+  p[0] *= (unsigned _BitInt(2110)) r;
+  p[1] *= (unsigned _BitInt(2110)) s;
+  p[2] *= (unsigned _BitInt(2110)) t;
+  p[3] *= (unsigned _BitInt(2110)) u;
+}
+
+void
+f4 (_BitInt(4094) *p, int r, _BitInt(115) s, _BitInt(128) t, _BitInt(231) u)
+{
+  p[0] /= (unsigned _BitInt(2110)) r;
+  p[1] /= (unsigned _BitInt(2110)) s;
+  p[2] /= (unsigned _BitInt(2110)) t;
+  p[3] /= (unsigned _BitInt(2110)) u;
+}
+
+void
+f5 (unsigned _BitInt(4096) *p, int r, _BitInt(115) s, _BitInt(128) t, _BitInt(231) u)
+{
+  p[0] *= (unsigned _BitInt(2048)) r;
+  p[1] *= (unsigned _BitInt(2048)) s;
+  p[2] *= (unsigned _BitInt(2048)) t;
+  p[3] *= (unsigned _BitInt(2048)) u;
+}
+
+void
+f6 (unsigned _BitInt(4094) *p, int r, _BitInt(115) s, _BitInt(128) t, _BitInt(231) u)
+{
+  p[0] /= (unsigned _BitInt(2048)) r;
+  p[1] /= (unsigned _BitInt(2048)) s;
+  p[2] /= (unsigned _BitInt(2048)) t;
+  p[3] /= (unsigned _BitInt(2048)) u;
+}
+
+void
+f7 (unsigned _BitInt(4096) *p, int r, _BitInt(115) s, _BitInt(128) t, _BitInt(231) u)
+{
+  p[0] *= (unsigned _BitInt(2110)) r;
+  p[1] *= (unsigned _BitInt(2110)) s;
+  p[2] *= (unsigned _BitInt(2110)) t;
+  p[3] *= (unsigned _BitInt(2110)) u;
+}
+
+void
+f8 (unsigned _BitInt(4094) *p, int r, _BitInt(115) s, _BitInt(128) t, _BitInt(231) u)
+{
+  p[0] /= (unsigned _BitInt(2110)) r;
+  p[1] /= (unsigned _BitInt(2110)) s;
+  p[2] /= (unsigned _BitInt(2110)) t;
+  p[3] /= (unsigned _BitInt(2110)) u;
+}
+
+#if __SIZEOF_INT128__
+void
+f9 (_BitInt(4096) *p, __int128 r)
+{
+  p[0] *= (unsigned _BitInt(2048)) r;
+}
+
+void
+f10 (_BitInt(4094) *p, __int128 r)
+{
+  p[0] /= (unsigned _BitInt(2048)) r;
+}
+
+void
+f11 (_BitInt(4096) *p, __int128 r)
+{
+  p[0] *= (unsigned _BitInt(2110)) r;
+}
+
+void
+f12 (_BitInt(4094) *p, __int128 r)
+{
+  p[0] /= (unsigned _BitInt(2110)) r;
+}
+
+void
+f13 (unsigned _BitInt(4096) *p, __int128 r)
+{
+  p[0] *= (unsigned _BitInt(2048)) r;
+}
+
+void
+f14 (unsigned _BitInt(4094) *p, __int128 r)
+{
+  p[0] /= (unsigned _BitInt(2048)) r;
+}
+
+void
+f15 (unsigned _BitInt(4096) *p, __int128 r)
+{
+  p[0] *= (unsigned _BitInt(2110)) r;
+}
+
+void
+f16 (unsigned _BitInt(4094) *p, __int128 r)
+{
+  p[0] /= (unsigned _BitInt(2110)) r;
+}
+#endif
+#else
+int i;
+#endif
--- gcc/testsuite/gcc.dg/bitint-57.c.jj	2023-12-20 12:42:12.691772991 +0100
+++ gcc/testsuite/gcc.dg/bitint-57.c	2023-12-20 12:42:49.900250015 +0100
@@ -0,0 +1,21 @@
+/* PR tree-optimization/112941 */
+/* { dg-do compile { target bitint } } */
+/* { dg-options "-std=c23 -O1 -fno-tree-forwprop" } */
+
+#if __BITINT_MAXWIDTH__ >= 6384
+unsigned _BitInt(2049)
+foo (unsigned _BitInt(6384) x, _BitInt(8) y)
+{
+  unsigned _BitInt(6384) z = y;
+  return x * z;
+}
+
+_BitInt(2049)
+bar (unsigned _BitInt(6384) x, _BitInt(1023) y)
+{
+  unsigned _BitInt(6384) z = y;
+  return x * z;
+}
+#else
+int i;
+#endif
