[gcc(refs/vendors/ARM/heads/morello)] c: Add missing fold in build_binary_op

[Matthew Malcomson <matmal01@gcc.gnu.org>]

https://gcc.gnu.org/g:56b253703f286253cadc701e01984090766e3c15

commit 56b253703f286253cadc701e01984090766e3c15
Author: Alex Coplan <alex.coplan@arm.com>
Date:   Wed Sep 22 11:20:47 2021 +0100

    c: Add missing fold in build_binary_op
    
    In build_binary_op we call c_fully_fold on the address value operand
    before building a replace_address_value node, since c_fully_fold (which
    would otherwise be called later) can't fold inside replace_address_value
    nodes. However, this didn't account for possible c_maybe_const_expr
    nodes in the intcap expression itself. This adds a call to c_fully_fold
    for the intcap operand.
    
    gcc/c/ChangeLog:
    
            * c-typeck.c (build_binary_op): Also call c_fully_fold on the
            intcap operand before building a replace_address_value node.
    
    gcc/testsuite/ChangeLog:
    
            * gcc.target/aarch64/morello/intcap-fold-ice.c: New test.

Diff:
---
 gcc/c/c-typeck.c                                           | 3 ++-
 gcc/testsuite/gcc.target/aarch64/morello/intcap-fold-ice.c | 9 +++++++++
 2 files changed, 11 insertions(+), 1 deletion(-)

diff --git a/gcc/c/c-typeck.c b/gcc/c/c-typeck.c
index 5b6c6e186af..30a082b3144 100644
--- a/gcc/c/c-typeck.c
+++ b/gcc/c/c-typeck.c
@@ -12962,8 +12962,9 @@ build_binary_op (location_t location, enum tree_code code,
 	  intcap = convert (ic_type, intcap);
 
 	  /* We can't fold inside REPLACE_ADDRESS_VALUE calls, so ensure
-	     we've folded the address value expression.  */
+	     we've folded the operands.  */
 	  ret = c_fully_fold (ret, false, NULL);
+	  intcap = c_fully_fold (intcap, false, NULL);
 	  ret = fold_build_replace_address_value_loc (location, intcap, ret);
 	}
 
diff --git a/gcc/testsuite/gcc.target/aarch64/morello/intcap-fold-ice.c b/gcc/testsuite/gcc.target/aarch64/morello/intcap-fold-ice.c
new file mode 100644
index 00000000000..95b73f8f7bb
--- /dev/null
+++ b/gcc/testsuite/gcc.target/aarch64/morello/intcap-fold-ice.c
@@ -0,0 +1,9 @@
+/* { dg-do compile } */
+
+/* This was ICEing due to a missing fold when building
+   replace_address_value nodes in the C frontend.  */
+
+struct {
+  __uintcap_t a;
+} * b;
+void c() { long a = (b ? b->a : 0) + a; }