[gcc r12-2850] middle-end/101858 - avoid shift of pointer in folding

[gcc r12-2850] middle-end/101858 - avoid shift of pointer in folding

[Richard Biener]

https://gcc.gnu.org/g:d7e91f4894f6a1a2daeec5cbe1e912bb896b9f7a

commit r12-2850-gd7e91f4894f6a1a2daeec5cbe1e912bb896b9f7a
Author: Richard Biener <rguenther@suse.de>
Date:   Wed Aug 11 10:26:18 2021 +0200

    middle-end/101858 - avoid shift of pointer in folding
    
    This makes sure to not generate a shift of pointer types in
    simplification of X < (cast) (1 << Y).
    
    2021-08-11  Richard Biener  <rguenther@suse.de>
    
            PR middle-end/101858
            * fold-const.c (fold_binary_loc): Guard simplification
            of  X < (cast) (1 << Y) to integer types.
    
            * gcc.dg/pr101858.c: New testcase.

Diff:
---
 gcc/fold-const.c                | 2 ++
 gcc/testsuite/gcc.dg/pr101858.c | 9 +++++++++
 2 files changed, 11 insertions(+)

diff --git a/gcc/fold-const.c b/gcc/fold-const.c
index 7dcecc9a5c0..ff23f12f33c 100644
--- a/gcc/fold-const.c
+++ b/gcc/fold-const.c
@@ -12497,6 +12497,8 @@ fold_binary_loc (location_t loc, enum tree_code code, tree type,
 	 we can't optimize this.  E.g. (unsigned long long) (1 << Y) for Y
 	 31 might be 0xffffffff80000000.  */
       if ((code == LT_EXPR || code == GE_EXPR)
+	  && (INTEGRAL_TYPE_P (TREE_TYPE (arg0))
+	      || VECTOR_INTEGER_TYPE_P (TREE_TYPE (arg0)))
 	  && TYPE_UNSIGNED (TREE_TYPE (arg0))
 	  && CONVERT_EXPR_P (arg1)
 	  && TREE_CODE (TREE_OPERAND (arg1, 0)) == LSHIFT_EXPR
diff --git a/gcc/testsuite/gcc.dg/pr101858.c b/gcc/testsuite/gcc.dg/pr101858.c
new file mode 100644
index 00000000000..61fcca60982
--- /dev/null
+++ b/gcc/testsuite/gcc.dg/pr101858.c
@@ -0,0 +1,9 @@
+/* { dg-do compile } */
+/* { dg-options "-w" } */
+
+int foo(int a)
+{
+  if (a < (int*)((__INTPTR_TYPE__)1 << a))
+    a = 0;
+  return a;
+}