i386.md: Add two new peephole2 to avoid mov followed by arithmetic with memory operands.

gcc:
2009-02-06  Paolo Bonzini  <bonzini@gnu.org>

	* config/i386/i386.md: Add two new peephole2 to avoid mov followed
	by arithmetic with memory operands.
	* config/i386/predicates.md (commutative_operator): New.

gcc/testsuite:
2009-02-06  Paolo Bonzini  <bonzini@gnu.org>

	* gcc.target/i386/pr38824.c: New testcase.

From-SVN: r144098

5 files changed, 67 insertions, 0 deletions

diff --git a/gcc/ChangeLog b/gcc/ChangeLog
index 1d32e09..4dd1672 100644
--- a/gcc/ChangeLog
+++ b/gcc/ChangeLog
@@ -1,3 +1,9 @@
+2009-02-11  Paolo Bonzini  <bonzini@gnu.org>
+
+	* config/i386/i386.md: Add two new peephole2 to avoid mov followed
+	by arithmetic with memory operands.
+	* config/i386/predicates.md (commutative_operator): New.
+
 2009-02-10  Janis Johnson  <janis187@us.ibm.com>
 
 	* doc/extend.texi (Fixed-Point Types): Break long paragraphs into
diff --git a/gcc/config/i386/i386.md b/gcc/config/i386/i386.md
index 89a3b17..7a4511f 100644
--- a/gcc/config/i386/i386.md
+++ b/gcc/config/i386/i386.md
@@ -20706,6 +20706,38 @@
               (clobber (reg:CC FLAGS_REG))])]
   "")
 
+;; Prefer Load+RegOp to Mov+MemOp.  Watch out for cases when the memory address
+;; refers to the destination of the load!
+
+(define_peephole2
+  [(set (match_operand:SI 0 "register_operand" "")
+        (match_operand:SI 1 "register_operand" ""))
+   (parallel [(set (match_dup 0)
+                   (match_operator:SI 3 "commutative_operator"
+                     [(match_dup 0)
+                      (match_operand:SI 2 "memory_operand" "")]))
+              (clobber (reg:CC FLAGS_REG))])]
+  "operands[0] != operands[1]"
+  [(set (match_dup 0) (match_dup 4))
+   (parallel [(set (match_dup 0)
+                   (match_op_dup 3 [(match_dup 0) (match_dup 1)]))
+              (clobber (reg:CC FLAGS_REG))])]
+  "operands[4] = simplify_replace_rtx (operands[2], operands[0], operands[1]);")
+
+(define_peephole2
+  [(set (match_operand 0 "register_operand" "")
+        (match_operand 1 "register_operand" ""))
+   (set (match_dup 0)
+                   (match_operator 3 "commutative_operator"
+                     [(match_dup 0)
+                      (match_operand 2 "memory_operand" "")]))]
+  "operands[0] != operands[1]
+   && (MMX_REG_P (operands[0]) || SSE_REG_P (operands[0]))"
+  [(set (match_dup 0) (match_dup 2))
+   (set (match_dup 0)
+        (match_op_dup 3 [(match_dup 0) (match_dup 1)]))]
+  "")
+
 ; Don't do logical operations with memory outputs
 ;
 ; These two don't make sense for PPro/PII -- we're expanding a 4-uop
diff --git a/gcc/config/i386/predicates.md b/gcc/config/i386/predicates.md
index bdac210..a8c01ad 100644
--- a/gcc/config/i386/predicates.md
+++ b/gcc/config/i386/predicates.md
@@ -1050,6 +1050,10 @@
   (match_code "plus,mult,and,ior,xor,smin,smax,umin,umax,compare,minus,div,
 	       mod,udiv,umod,ashift,rotate,ashiftrt,lshiftrt,rotatert"))
 
+;; Return true for COMMUTATIVE_P.
+(define_predicate "commutative_operator"
+  (match_code "plus,mult,and,ior,xor,smin,smax,umin,umax"))
+
 ;; Return 1 if OP is a binary operator that can be promoted to wider mode.
 (define_predicate "promotable_binary_operator"
   (ior (match_code "plus,and,ior,xor,ashift")
diff --git a/gcc/testsuite/ChangeLog b/gcc/testsuite/ChangeLog
index 52817fa..9b64184 100644
--- a/gcc/testsuite/ChangeLog
+++ b/gcc/testsuite/ChangeLog
@@ -1,3 +1,7 @@
+2009-02-11  Paolo Bonzini  <bonzini@gnu.org>
+
+	* gcc.target/i386/pr38824.c: New testcase.
+
 2009-02-11  Jason Merrill  <jason@redhat.com>
 
 	PR c++/38649
diff --git a/gcc/testsuite/gcc.target/i386/pr38824.c b/gcc/testsuite/gcc.target/i386/pr38824.c
new file mode 100644
index 0000000..637abfd
--- /dev/null
+++ b/gcc/testsuite/gcc.target/i386/pr38824.c
@@ -0,0 +1,21 @@
+/* { dg-do compile } */
+/* { dg-options "-O2 -msse" } */
+
+typedef float v4sf __attribute__ ((__vector_size__ (16)));
+
+void bench_1(float * out, float * in, float f, unsigned int n)
+{
+    n /= 4;
+    v4sf scalar = { f, f, f, f };
+    do
+    {
+        v4sf arg = *(v4sf *)in;
+        v4sf result = arg + scalar;
+        *(v4sf *) out = result;
+        in += 4;
+        out += 4;
+    }
+    while (--n);
+}
+
+/* { dg-final { scan-assembler-not "addps\[^\\n\]*%\[er\]" } } */