re PR rtl-optimization/85925 (compilation of masking with 257 goes wrong in combine at -02)

	PR rtl-optimization/85925
	* rtl.h (word_register_operation_p): New predicate.
	* combine.c (record_dead_and_set_regs_1): Only apply specific handling
	for WORD_REGISTER_OPERATIONS targets to word_register_operation_p RTX.
	* rtlanal.c (nonzero_bits1): Likewise.  Adjust couple of comments.
	(num_sign_bit_copies1): Likewise.

From-SVN: r266302

1 files changed, 19 insertions, 0 deletions

diff --git a/gcc/rtl.h b/gcc/rtl.h
index 68d3cea..4114cd0 100644
--- a/gcc/rtl.h
+++ b/gcc/rtl.h
@@ -4374,6 +4374,25 @@ strip_offset_and_add (rtx x, poly_int64_pod *offset)
   return x;
 }
 
+/* Return true if X is an operation that always operates on the full
+   registers for WORD_REGISTER_OPERATIONS architectures.  */
+
+inline bool
+word_register_operation_p (const_rtx x)
+{
+  switch (GET_CODE (x))
+    {
+    case ROTATE:
+    case ROTATERT:
+    case SIGN_EXTRACT:
+    case ZERO_EXTRACT:
+      return false;
+    
+    default:
+      return true;
+    }
+}
+    
 /* gtype-desc.c.  */
 extern void gt_ggc_mx (rtx &);
 extern void gt_pch_nx (rtx &);