tree-optimization/116406 - ICE with int<->float punning prevention

The following does away with the idea to use non-symmetrical
testing of mode_can_transfer_bits in hash-table equality testing.
It isn't feasible to always control query order to maintain
consistency.

	PR tree-optimization/116406
	* tree-ssa-sccvn.cc (vn_reference_eq): Never equate
	float and int when the float mode cannot transfer bits.
	Do not try to anticipate which is the mode we actually load
	from.

	* gcc.dg/tree-ssa/pr116406.c: New testcase.
	* gcc.dg/tree-ssa/ssa-pre-30.c: On x86 dd -msse -mfpmath=sse.

diff --git a/gcc/testsuite/gcc.dg/tree-ssa/pr116406.c b/gcc/testsuite/gcc.dg/tree-ssa/pr116406.c
new file mode 100644 (file)
index 0000000..6643c49
--- /dev/null
+++ b/gcc/testsuite/gcc.dg/tree-ssa/pr116406.c
@@ -0,0 +1,21 @@
+/* { dg-do compile } */
+/* { dg-options "-Os -finstrument-functions-once" } */
+/* { dg-additional-options "-mfpmath=387" { target { x86_64-*-* i?86-*-* } } } */
+
+typedef union {
+  float f32;
+  double f64;
+  long i64;
+} U;
+
+_Bool
+foo (int c, U u)
+{
+  switch (c)
+    {
+    case 1:
+      return u.f32 - u.f64;
+    case 0:
+      return u.i64;
+    }
+}

diff --git a/gcc/testsuite/gcc.dg/tree-ssa/ssa-pre-30.c b/gcc/testsuite/gcc.dg/tree-ssa/ssa-pre-30.c
index cf9317372d64f91df9e851fe3d61db3bd6b44b83..29dc181233801bd7fe8e56d24b5b507509c5c9ae 100644 (file)
--- a/gcc/testsuite/gcc.dg/tree-ssa/ssa-pre-30.c
+++ b/gcc/testsuite/gcc.dg/tree-ssa/ssa-pre-30.c
@@ -1,6 +1,7 @@
 /* { dg-do compile } */
 /* { dg-require-effective-target int32 } */
 /* { dg-options "-O2 -fdump-tree-pre-details" } */
+/* { dg-additional-options "-msse -mfpmath=sse" { target { x86_64-*-* i?86-*-* } } } */
 
 int f;
 int g;

diff --git a/gcc/tree-ssa-sccvn.cc b/gcc/tree-ssa-sccvn.cc
index 4370d09d9d8cebe27f4713e86e52ef13d7de0ee0..abf7d38d15cb3a22db5cd980c5783707b71a089d 100644 (file)
--- a/gcc/tree-ssa-sccvn.cc
+++ b/gcc/tree-ssa-sccvn.cc
@@ -838,7 +838,8 @@ vn_reference_eq (const_vn_reference_t const vr1, const_vn_reference_t const vr2)
        return false;
     }
   else if (TYPE_MODE (vr1->type) != TYPE_MODE (vr2->type)
-          && !mode_can_transfer_bits (TYPE_MODE (vr1->type)))
+          && (!mode_can_transfer_bits (TYPE_MODE (vr1->type))
+              || !mode_can_transfer_bits (TYPE_MODE (vr2->type))))
     return false;
 
   i = 0;