From: Richard Sandiford <richard.sandiford@linaro.org>
Date: Wed, 1 Nov 2017 17:06:17 +0000 (+0000)
Subject: revert: combine.c (can_change_dest_mode): Reject changes in REGMODE_NATURAL_SIZE.
X-Git-Tag: basepoints/gcc-9~3716
X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=37a2c475252b26895732fefbbb0050c864ba698d;p=thirdparty%2Fgcc.git

revert: combine.c (can_change_dest_mode): Reject changes in REGMODE_NATURAL_SIZE.

2017-11-01  Richard Sandiford  <richard.sandiford@linaro.org>

gcc/
	Revert accidental duplicate:

	* combine.c (can_change_dest_mode): Reject changes in
	REGMODE_NATURAL_SIZE.

From-SVN: r254316
---

diff --git a/gcc/ChangeLog b/gcc/ChangeLog
index cc51a722b36c..adf8cf308e9a 100644
--- a/gcc/ChangeLog
+++ b/gcc/ChangeLog
@@ -1,3 +1,10 @@
+2017-11-01  Richard Sandiford  <richard.sandiford@linaro.org>
+
+	Revert accidental duplicate:
+
+	* combine.c (can_change_dest_mode): Reject changes in
+	REGMODE_NATURAL_SIZE.
+
 2017-11-01  Segher Boessenkool  <segher@kernel.crashing.org>
 
 	PR rtl-optimization/64682
diff --git a/gcc/combine.c b/gcc/combine.c
index d5b15cb3caae..968e6871e996 100644
--- a/gcc/combine.c
+++ b/gcc/combine.c
@@ -2478,12 +2478,6 @@ can_change_dest_mode (rtx x, int added_sets, machine_mode mode)
       != REGMODE_NATURAL_SIZE (GET_MODE (x)))
     return false;
 
-  /* Don't change between modes with different underlying register sizes,
-     since this could lead to invalid subregs.  */
-  if (REGMODE_NATURAL_SIZE (mode)
-      != REGMODE_NATURAL_SIZE (GET_MODE (x)))
-    return false;
-
   regno = REGNO (x);
   /* Allow hard registers if the new mode is legal, and occupies no more
      registers than the old mode.  */