(REGISTER_MOVE_COST): Decrease cost for move from

SHIFT_REGS to avoid regclass overflow.

From-SVN: r5986

diff --git a/gcc/config/pa/pa.h b/gcc/config/pa/pa.h
index 7665c4722e7b2a8b05647a87b19ddf94a403ea9a..f683db389209d4f5436613a6566742c837d9a39d 100644 (file)
--- a/gcc/config/pa/pa.h
+++ b/gcc/config/pa/pa.h
@@ -1475,14 +1475,15 @@ while (0)
 /* Compute extra cost of moving data between one register class
    and another.
 
-   Make moves from SAR so expensive they should never happen.
+   Make moves from SAR so expensive they should never happen.  We used to
+   have 0xffff here, but that generates overflow in rare cases.
 
    Copies involving a FP register and a non-FP register are relatively 
    expensive because they must go through memory.
 
    Other copies are reasonably cheap.  */
 #define REGISTER_MOVE_COST(CLASS1, CLASS2) \
- (CLASS1 == SHIFT_REGS ? 0xffff                                        \
+ (CLASS1 == SHIFT_REGS ? 0x100                                 \
   : FP_REG_CLASS_P (CLASS1) && ! FP_REG_CLASS_P (CLASS2) ? 16  \
   : FP_REG_CLASS_P (CLASS2) && ! FP_REG_CLASS_P (CLASS1) ? 16  \
   : 2)