From fb664a2cba8002496836cffe6381ad3f834df6cc Mon Sep 17 00:00:00 2001 From: Richard Guenther Date: Tue, 17 May 2005 09:00:03 +0000 Subject: [PATCH] re PR middle-end/21595 (__builtin_constant_p(&"Hello"[0]) is true for C but not for C++) 2005-05-17 Richard Guenther PR middle-end/21595 * builtins.c (fold_builtin_constant_p): Handle &"string cst"[0] as constant. * g++.dg/tree-ssa/builtin1.C: New testcase. From-SVN: r99825 --- gcc/ChangeLog | 6 ++++++ gcc/builtins.c | 13 ++++++++++--- gcc/testsuite/ChangeLog | 5 +++++ gcc/testsuite/g++.dg/tree-ssa/builtin1.C | 10 ++++++++++ 4 files changed, 31 insertions(+), 3 deletions(-) create mode 100644 gcc/testsuite/g++.dg/tree-ssa/builtin1.C diff --git a/gcc/ChangeLog b/gcc/ChangeLog index 82233e9ee9bb..449a1b49c257 100644 --- a/gcc/ChangeLog +++ b/gcc/ChangeLog @@ -1,3 +1,9 @@ +2005-05-17 Richard Guenther + + PR middle-end/21595 + * builtins.c (fold_builtin_constant_p): Handle + &"string cst"[0] as constant. + 2005-05-17 Richard Henderson * config/i386/sse.md (mulv16qi3, mulv2di3): New. diff --git a/gcc/builtins.c b/gcc/builtins.c index 8d4fc3379fd8..cdc5cebcbc6d 100644 --- a/gcc/builtins.c +++ b/gcc/builtins.c @@ -6338,10 +6338,17 @@ fold_builtin_constant_p (tree arglist) /* If we know this is a constant, emit the constant of one. */ if (CONSTANT_CLASS_P (arglist) || (TREE_CODE (arglist) == CONSTRUCTOR - && TREE_CONSTANT (arglist)) - || (TREE_CODE (arglist) == ADDR_EXPR - && TREE_CODE (TREE_OPERAND (arglist, 0)) == STRING_CST)) + && TREE_CONSTANT (arglist))) return integer_one_node; + if (TREE_CODE (arglist) == ADDR_EXPR) + { + tree op = TREE_OPERAND (arglist, 0); + if (TREE_CODE (op) == STRING_CST + || (TREE_CODE (op) == ARRAY_REF + && integer_zerop (TREE_OPERAND (op, 1)) + && TREE_CODE (TREE_OPERAND (op, 0)) == STRING_CST)) + return integer_one_node; + } /* If this expression has side effects, show we don't know it to be a constant. Likewise if it's a pointer or aggregate type since in diff --git a/gcc/testsuite/ChangeLog b/gcc/testsuite/ChangeLog index 367947b929bb..b6ce026b1971 100644 --- a/gcc/testsuite/ChangeLog +++ b/gcc/testsuite/ChangeLog @@ -1,3 +1,8 @@ +2005-05-17 Richard Guenther + + PR middle-end/21595 + * g++.dg/tree-ssa/builtin1.C: New testcase. + 2005-05-17 Jakub Jelinek PR c++/21454 diff --git a/gcc/testsuite/g++.dg/tree-ssa/builtin1.C b/gcc/testsuite/g++.dg/tree-ssa/builtin1.C new file mode 100644 index 000000000000..76813cb8dddf --- /dev/null +++ b/gcc/testsuite/g++.dg/tree-ssa/builtin1.C @@ -0,0 +1,10 @@ +// { dg-do link } + +extern void link_error(); + +int main() +{ + if (! __builtin_constant_p (&"Hello"[0])) + link_error(); + return 0; +}