From d7e91f4894f6a1a2daeec5cbe1e912bb896b9f7a Mon Sep 17 00:00:00 2001 From: Richard Biener Date: Wed, 11 Aug 2021 10:26:18 +0200 Subject: [PATCH] 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 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. --- gcc/fold-const.c | 2 ++ gcc/testsuite/gcc.dg/pr101858.c | 9 +++++++++ 2 files changed, 11 insertions(+) create mode 100644 gcc/testsuite/gcc.dg/pr101858.c diff --git a/gcc/fold-const.c b/gcc/fold-const.c index 7dcecc9a5c08..ff23f12f33c9 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 000000000000..61fcca60982c --- /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; +} -- 2.47.2