(expand_unop): Try subtraction from zero if there isn't a

negate library function.


git-svn-id: svn+ssh://gcc.gnu.org/svn/gcc/trunk@8485 138bc75d-0d04-0410-961f-82ee72b054a4

1 files changed, 11 insertions, 0 deletions

diff --git a/gcc/optabs.c b/gcc/optabs.c
index db68da8f9fb..724f36b58cb 100644
--- a/gcc/optabs.c
+++ b/gcc/optabs.c
@@ -2041,6 +2041,17 @@ expand_unop (mode, unoptab, op0, target, unsignedp)
 	}
     }
 
+  /* If there is no negate operation, try doing a subtract from zero.
+     The US Software GOFAST library needs this.  */
+  if (unoptab == neg_optab)
+    {    
+      rtx temp;
+      temp = expand_binop (mode, sub_optab, CONST0_RTX (mode), op0,
+			   target, unsignedp, OPTAB_LIB_WIDEN);
+      if (temp)
+	return temp;
+    }
+      
   return 0;
 }