From ca8e8301180fa71de1a76769fc038df2ab85dfeb Mon Sep 17 00:00:00 2001
From: Richard Biener <rguenther@suse.de>
Date: Tue, 11 May 2021 10:58:35 +0200
Subject: [PATCH] middle-end/100509 - avoid folding constant to aggregate type
When folding a constant initializer looking through aliases to
incompatible types can lead to us trying to fold a constant
to an aggregate type which can't work. Simply avoid trying
to constant fold non-register typed symbols.
2021-05-11 Richard Biener <rguenther@suse.de>
PR middle-end/100509
* gimple-fold.c (fold_gimple_assign): Only call
get_symbol_constant_value on register type symbols.
* gcc.dg/pr100509.c: New testcase.
---
gcc/gimple-fold.c | 3 ++-
gcc/testsuite/gcc.dg/pr100509.c | 9 +++++++++
2 files changed, 11 insertions(+), 1 deletion(-)
create mode 100644 gcc/testsuite/gcc.dg/pr100509.c
diff --git a/gcc/gimple-fold.c b/gcc/gimple-fold.c
index 768ef89d8762..6beb4f3d3050 100644
--- a/gcc/gimple-fold.c
+++ b/gcc/gimple-fold.c
@@ -547,7 +547,8 @@ fold_gimple_assign (gimple_stmt_iterator *si)
CONSTRUCTOR_ELTS (rhs));
}
- else if (DECL_P (rhs))
+ else if (DECL_P (rhs)
+ && is_gimple_reg_type (TREE_TYPE (rhs)))
return get_symbol_constant_value (rhs);
}
break;
diff --git a/gcc/testsuite/gcc.dg/pr100509.c b/gcc/testsuite/gcc.dg/pr100509.c
new file mode 100644
index 000000000000..9405e2a27df8
--- /dev/null
+++ b/gcc/testsuite/gcc.dg/pr100509.c
@@ -0,0 +1,9 @@
+/* { dg-do compile } */
+/* { dg-options "-O" } */
+
+struct X {
+ int a;
+};
+const int a = 0;
+static struct X A __attribute__((alias("a")));
+void foo() { struct X b = A; }
--
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