From: Adam Nemet <anemet@caviumnetworks.com>
Date: Sat, 18 Jul 2009 21:55:40 +0000 (+0000)
Subject: combine.c (make_compound_operation): If force_to_mode re-expanded the compound use... 
X-Git-Tag: releases/gcc-4.5.0~4512
X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=827f4079406b72fce7b49a29abe60ecb801462d5;p=thirdparty%2Fgcc.git

combine.c (make_compound_operation): If force_to_mode re-expanded the compound use gen_lowpart instead to convert to...

	* combine.c (make_compound_operation) <SUBREG>: If force_to_mode
	re-expanded the compound use gen_lowpart instead to convert to the
	desired mode.

testsuite/
	* gcc.target/mips/ext-2.c: New test.

From-SVN: r149781
---

diff --git a/gcc/ChangeLog b/gcc/ChangeLog
index c087253a80a7..8ad42bf6ac5b 100644
--- a/gcc/ChangeLog
+++ b/gcc/ChangeLog
@@ -1,3 +1,9 @@
+2009-07-18  Adam Nemet  <anemet@caviumnetworks.com>
+
+	* combine.c (make_compound_operation) <SUBREG>: If force_to_mode
+	re-expanded the compound use gen_lowpart instead to convert to the
+	desired mode.
+
 2009-07-18  Adam Nemet  <anemet@caviumnetworks.com>
 
 	* combine.c (try_widen_shift_mode): Add COUNT, OUTER_CODE and
diff --git a/gcc/combine.c b/gcc/combine.c
index 39daf2881d4f..3f39bc3b286a 100644
--- a/gcc/combine.c
+++ b/gcc/combine.c
@@ -7061,6 +7061,12 @@ make_compound_operation (rtx x, enum rtx_code in_code)
 	    if (GET_CODE (newer) != SUBREG)
 	      newer = make_compound_operation (newer, in_code);
 
+	    /* force_to_mode can expand compounds.  If it just re-expanded the
+	       compound use gen_lowpart instead to convert to the desired
+	       mode.  */
+	    if (rtx_equal_p (newer, x))
+	      return gen_lowpart (GET_MODE (x), tem);
+
 	    return newer;
 	  }
 
diff --git a/gcc/testsuite/ChangeLog b/gcc/testsuite/ChangeLog
index 3200817c4e1e..b1f86982294f 100644
--- a/gcc/testsuite/ChangeLog
+++ b/gcc/testsuite/ChangeLog
@@ -1,3 +1,7 @@
+2009-07-18  Adam Nemet  <anemet@caviumnetworks.com>
+
+	* gcc.target/mips/ext-2.c: New test.
+
 2009-07-18  Adam Nemet  <anemet@caviumnetworks.com>
 
 	* gcc.target/mips/octeon-exts-7.c: New test.
diff --git a/gcc/testsuite/gcc.target/mips/ext-2.c b/gcc/testsuite/gcc.target/mips/ext-2.c
new file mode 100644
index 000000000000..8d502b21b10f
--- /dev/null
+++ b/gcc/testsuite/gcc.target/mips/ext-2.c
@@ -0,0 +1,14 @@
+/* Turn the truncate,zero_extend,lshiftrt sequence before the or into a
+   zero_extract.  The truncate is due to TARGET_PROMOTE_PROTOTYPES, the
+   zero_extend to PROMOTE_MODE.  */
+/* { dg-do compile } */
+/* { dg-options "-O isa_rev>=2 -mgp64" } */
+/* { dg-final { scan-assembler "\tdext\t" } } */
+/* { dg-final { scan-assembler-not "and" } } */
+/* { dg-final { scan-assembler-not "srl" } } */
+
+void
+f (unsigned char x, unsigned char *r)
+{
+  *r = 0x50 | (x >> 4);
+}