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[Bug rtl-optimization/21329] optimize i386 block copy


------- Additional Comments From vda at port dot imtp dot ilyichevsk dot odessa dot ua  2005-05-02 09:10 -------
BTW, see above comment: gcc -O2 allocated 24 bytes on stack
and never uset them. ?!

Now, unoptimized compilation comparison:

--- t.s	Mon May  2 11:41:20 2005
+++ t-new.s	Mon May  2 11:39:40 2005
@@ -32,8 +32,8 @@
 	movl	$t21, %edi
 	movl	$w21, %esi
 	cld
-	movl	$9, %ecx
-	rep
+	movsl
+	movsl
 	movsb
 	popl	%esi
 	popl	%edi
@@ -50,9 +50,9 @@
 	movl	$t22, %edi
 	movl	$w22, %esi
 	cld
-	movl	$10, %ecx
-	rep
-	movsb
+	movsl
+	movsl
+	movsw
 	popl	%esi
 	popl	%edi
 	leave
@@ -68,8 +68,9 @@
 	movl	$t23, %edi
 	movl	$w23, %esi
 	cld
-	movl	$11, %ecx
-	rep
+	movsl
+	movsl
+	movsw
 	movsb
 	popl	%esi
 	popl	%edi
@@ -86,9 +87,8 @@
 	movl	$t30, %edi
 	movl	$w30, %esi
 	cld
-	movl	$3, %eax
-	movl	%eax, %ecx
-	rep
+	movsl
+	movsl
 	movsl
 	popl	%esi
 	popl	%edi
@@ -105,9 +105,9 @@
 	movl	$t40, %edi
 	movl	$w40, %esi
 	cld
-	movl	$4, %eax
-	movl	%eax, %ecx
-	rep
+	movsl
+	movsl
+	movsl
 	movsl
 	popl	%esi
 	popl	%edi
@@ -168,34 +168,34 @@
 	movl	$t21, %edi
 	movl	$w21, %esi
 	cld
-	movl	$9, %ecx
-	rep
+	movsl
+	movsl
 	movsb
 	movl	$t22, %edi
 	movl	$w22, %esi
 	cld
-	movl	$10, %ecx
-	rep
-	movsb
+	movsl
+	movsl
+	movsw
 	movl	$t23, %edi
 	movl	$w23, %esi
 	cld
-	movl	$11, %ecx
-	rep
+	movsl
+	movsl
+	movsw
 	movsb
 	movl	$t30, %edi
 	movl	$w30, %esi
 	cld
-	movl	$3, %eax
-	movl	%eax, %ecx
-	rep
+	movsl
+	movsl
 	movsl
 	movl	$t40, %edi
 	movl	$w40, %esi
 	cld
-	movl	$4, %eax
-	movl	%eax, %ecx
-	rep
+	movsl
+	movsl
+	movsl
 	movsl
 	movl	$t50, %edi
 	movl	$w50, %esi


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=21329


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