Mercurial > hg > truffle

diff src/share/vm/opto/mulnode.cpp @ 404:78c058bc5cdc

Find changesets by keywords (author, files, the commit message), revision number or hash, or revset expression.
6717150: improper constant folding of subnormal strictfp multiplications and divides Summary: suppress constant folding of double divides and multiplications on ia32 Reviewed-by: never
author rasbold
date Tue, 14 Oct 2008 06:58:58 -0700
parents d1605aabd0a1
children 3b5ac9e7e6ea
line wrap: on
line diff
--- a/src/share/vm/opto/mulnode.cpp	Fri Oct 10 09:47:56 2008 -0700
+++ b/src/share/vm/opto/mulnode.cpp	Tue Oct 14 06:58:58 2008 -0700
@@ -152,6 +152,14 @@
   if( t1 == Type::BOTTOM || t2 == Type::BOTTOM )
     return bottom_type();
 
+#if defined(IA32)
+  // Can't trust native compilers to properly fold strict double
+  // multiplication with round-to-zero on this platform.
+  if (op == Op_MulD && phase->C->method()->is_strict()) {
+    return TypeD::DOUBLE;
+  }
+#endif
+
   return mul_ring(t1,t2);            // Local flavor of type multiplication
 }
 
@@ -360,7 +368,7 @@
 // Compute the product type of two double ranges into this node.
 const Type *MulDNode::mul_ring(const Type *t0, const Type *t1) const {
   if( t0 == Type::DOUBLE || t1 == Type::DOUBLE ) return Type::DOUBLE;
-  // We must be adding 2 double constants.
+  // We must be multiplying 2 double constants.
   return TypeD::make( t0->getd() * t1->getd() );
 }