From: jakub <jakub@138bc75d-0d04-0410-961f-82ee72b054a4>
Date: Fri, 1 Apr 2016 16:08:21 +0000 (+0000)
Subject: 	PR rtl-optimization/70467
X-Git-Url: http://git.ipfire.org/gitweb.cgi?a=commitdiff_plain;h=0edb9bfe8b60013cc0d6aa6dfc4039b2213f1f6d;p=thirdparty%2Fgcc.git

	PR rtl-optimization/70467
	* config/i386/i386.md (*add<dwi>3_doubleword, *sub<dwi>3_doubleword):
	If low word of the last operand is 0, just emit addition/subtraction
	for the high word.

	* gcc.target/i386/pr70467-2.c: New test.


git-svn-id: svn+ssh://gcc.gnu.org/svn/gcc/trunk@234679 138bc75d-0d04-0410-961f-82ee72b054a4
---

diff --git a/gcc/ChangeLog b/gcc/ChangeLog
index de3b8c575434..81d887974727 100644
--- a/gcc/ChangeLog
+++ b/gcc/ChangeLog
@@ -1,3 +1,10 @@
+2016-04-01  Jakub Jelinek  <jakub@redhat.com>
+
+	PR rtl-optimization/70467
+	* config/i386/i386.md (*add<dwi>3_doubleword, *sub<dwi>3_doubleword):
+	If low word of the last operand is 0, just emit addition/subtraction
+	for the high word.
+
 2016-04-01  Andreas Krebbel  <krebbel@linux.vnet.ibm.com>
 
 	PR target/70404
diff --git a/gcc/config/i386/i386.md b/gcc/config/i386/i386.md
index f324ea7ea419..09da69e7e44d 100644
--- a/gcc/config/i386/i386.md
+++ b/gcc/config/i386/i386.md
@@ -5449,7 +5449,14 @@
 		       (match_dup 4))
 		     (match_dup 5)))
 	      (clobber (reg:CC FLAGS_REG))])]
-  "split_double_mode (<DWI>mode, &operands[0], 3, &operands[0], &operands[3]);")
+{
+  split_double_mode (<DWI>mode, &operands[0], 3, &operands[0], &operands[3]);
+  if (operands[2] == const0_rtx)
+    {
+      ix86_expand_binary_operator (PLUS, <MODE>mode, &operands[3]);
+      DONE;
+    }
+})
 
 (define_insn "*add<mode>_1"
   [(set (match_operand:SWI48 0 "nonimmediate_operand" "=r,rm,r,r")
@@ -6379,7 +6386,14 @@
 		       (ltu:DWIH (reg:CC FLAGS_REG) (const_int 0)))
 		     (match_dup 5)))
 	      (clobber (reg:CC FLAGS_REG))])]
-  "split_double_mode (<DWI>mode, &operands[0], 3, &operands[0], &operands[3]);")
+{
+  split_double_mode (<DWI>mode, &operands[0], 3, &operands[0], &operands[3]);
+  if (operands[2] == const0_rtx)
+    {
+      ix86_expand_binary_operator (MINUS, <MODE>mode, &operands[3]);
+      DONE;
+    }
+})
 
 (define_insn "*sub<mode>_1"
   [(set (match_operand:SWI 0 "nonimmediate_operand" "=<r>m,<r>")
diff --git a/gcc/testsuite/ChangeLog b/gcc/testsuite/ChangeLog
index a4a1df51afcf..e908caaf4d1e 100644
--- a/gcc/testsuite/ChangeLog
+++ b/gcc/testsuite/ChangeLog
@@ -1,3 +1,8 @@
+2016-04-01  Jakub Jelinek  <jakub@redhat.com>
+
+	PR rtl-optimization/70467
+	* gcc.target/i386/pr70467-2.c: New test.
+
 2016-04-01  Jakub Jelinek  <jakub@redhat.com>
 	    Marek Polacek  <polacek@redhat.com>
 
diff --git a/gcc/testsuite/gcc.target/i386/pr70467-2.c b/gcc/testsuite/gcc.target/i386/pr70467-2.c
new file mode 100644
index 000000000000..4c1715c87e53
--- /dev/null
+++ b/gcc/testsuite/gcc.target/i386/pr70467-2.c
@@ -0,0 +1,20 @@
+/* PR rtl-optimization/70467 */
+/* { dg-do compile { target ia32 } } */
+/* { dg-options "-O2" } */
+
+unsigned long long
+foo (unsigned long long x)
+{
+  return x + 0x12345600000000ULL;
+}
+
+unsigned long long
+bar (unsigned long long x)
+{
+  return x - 0x12345600000000ULL;
+}
+
+/* { dg-final { scan-assembler-not "addl\[ \t\]*.0," } } */
+/* { dg-final { scan-assembler-not "subl\[ \t\]*.0," } } */
+/* { dg-final { scan-assembler-not "adcl\[^\n\r\]*%" } } */
+/* { dg-final { scan-assembler-not "sbbl\[^\n\r\]*%" } } */