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Fix PR70948

Message ID alpine.LSU.2.11.1605061422200.13384@t29.fhfr.qr
State New
Headers show

Commit Message

Richard Biener May 6, 2016, 12:24 p.m. UTC 
The following fixes PR70948, a failure of PTA considering all
fields of va_list being clobbered (assigned from NONLOCAL) for
__builtin_va_start.  With the new pointer-vs.-decl comparison
optimization this bug manifests as a miscompile of
gcc.c-torture/execute/va-arg-pack-1.c on AARCH64.

Bootstrapped and tested on x86_64-unknown-linux-gnu, Jiong Wang
verified it fixes the aarch64 issue (I verified by dump inspection only).

Applied to trunk.

Richard.

2016-05-06  Richard Biener  <rguenther@suse.de>

	PR tree-optimization/70948
	* tree-ssa-structalias.c (find_func_aliases_for_builtin_call):
	Properly clobber all fields of va_list for __builtin_va_start.
diff mbox

Patch

Index: gcc/tree-ssa-structalias.c
===================================================================
--- gcc/tree-ssa-structalias.c	(revision 235945)
+++ gcc/tree-ssa-structalias.c	(working copy)
@@ -4492,7 +4492,7 @@  find_func_aliases_for_builtin_call (stru
 	  tree valist = gimple_call_arg (t, 0);
 	  struct constraint_expr rhs, *lhsp;
 	  unsigned i;
-	  get_constraint_for (valist, &lhsc);
+	  get_constraint_for_ptr_offset (valist, NULL_TREE, &lhsc);
 	  do_deref (&lhsc);
 	  /* The va_list gets access to pointers in variadic
 	     arguments.  Which we know in the case of IPA analysis