combine: Check for paradoxical subreg.

This adds a check for a paradoxical subreg in reg_subword_p ()
in order to prevent an ICE on s390 in try_combine () triggered
by the movqicc expander.

gcc/ChangeLog:

	* combine.cc (reg_subword_p): Check for paradoxical subreg.

diff --git a/gcc/combine.cc b/gcc/combine.cc
index 7683f82..c264ede 100644 (file)
--- a/gcc/combine.cc
+++ b/gcc/combine.cc
@@ -2411,6 +2411,7 @@ reg_subword_p (rtx x, rtx reg)
     x = XEXP (x, 0);
 
   return GET_CODE (x) == SUBREG
+        && !paradoxical_subreg_p (x)
         && SUBREG_REG (x) == reg
         && GET_MODE_CLASS (GET_MODE (x)) == MODE_INT;
 }