From: Richard Sandiford <richard.sandiford@linaro.org>
Date: Mon, 12 Jun 2017 16:06:38 +0000 (+0000)
Subject: Fix pessimistic DImode handling in combine.c:make_field_assignment
X-Git-Url: https://git.libre-soc.org/?a=commitdiff_plain;h=e701e0b9e8c74e5e93764556a447ea334e4e9389;p=gcc.git

Fix pessimistic DImode handling in combine.c:make_field_assignment

The make_field_assignment code:

      src = force_to_mode (src, mode,
		       GET_MODE_PRECISION (mode) >= HOST_BITS_PER_WIDE_INT
		       ? HOST_WIDE_INT_M1U
		       : (HOST_WIDE_INT_1U << len) - 1,
		       0);

would ignore the field length len for DImode, even though DImode can be
handled using HWIs.  I think the code should be testing len instead.

2017-06-12  Richard Sandiford  <richard.sandiford@linaro.org>

gcc/
	* combine.c (make_field_assignment): Check len rather than the mode
	precision when calling force_to_mode.

From-SVN: r249128
---

diff --git a/gcc/ChangeLog b/gcc/ChangeLog
index d4f4dee2714..cc5435d54a6 100644
--- a/gcc/ChangeLog
+++ b/gcc/ChangeLog
@@ -1,3 +1,8 @@
+2017-06-12  Richard Sandiford  <richard.sandiford@linaro.org>
+
+	* combine.c (make_field_assignment): Check len rather than the mode
+	precision when calling force_to_mode.
+
 2017-06-12  Georg-Johann Lay  <avr@gjlay.de>
 
 	Support multilibs and devices that see flash in RAM address range.
diff --git a/gcc/combine.c b/gcc/combine.c
index 39ef3c6ecb8..2d49bc2233c 100644
--- a/gcc/combine.c
+++ b/gcc/combine.c
@@ -9634,7 +9634,7 @@ make_field_assignment (rtx x)
 						     other, pos),
 			       dest);
   src = force_to_mode (src, mode,
-		       GET_MODE_PRECISION (mode) >= HOST_BITS_PER_WIDE_INT
+		       len >= HOST_BITS_PER_WIDE_INT
 		       ? HOST_WIDE_INT_M1U
 		       : (HOST_WIDE_INT_1U << len) - 1,
 		       0);