[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 09:00 --- Created an attachment (id=8790) -- (http://gcc.gnu.org/bugzilla/attachment.cgi?id=8790action=view) testcase -- http://gcc.gnu.org/bugzilla/show_bug.cgi?id=21329
[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 09:02 --- Created an attachment (id=8791) -- (http://gcc.gnu.org/bugzilla/attachment.cgi?id=8791action=view) patch against 4.0.0 -- http://gcc.gnu.org/bugzilla/show_bug.cgi?id=21329
[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 09:04 --- Comparison between old and new code (-O2): --- tO2.s Mon May 2 11:49:24 2005 +++ tO2-new.s Mon May 2 11:50:03 2005 @@ -35,8 +35,7 @@ movl$t21, %edi movl$w21, %esi cld - movl$2, %ecx - rep + movsl movsl movsb popl%esi @@ -55,8 +54,7 @@ movl$t22, %edi movl$w22, %esi cld - movl$2, %ecx - rep + movsl movsl movsw popl%esi @@ -75,8 +73,7 @@ movl$t23, %edi movl$w23, %esi cld - movl$2, %ecx - rep + movsl movsl movsw movsb @@ -96,8 +93,8 @@ movl$t30, %edi movl$w30, %esi cld - movl$3, %ecx - rep + movsl + movsl movsl popl%esi popl%edi @@ -115,8 +112,9 @@ movl$t40, %edi movl$w40, %esi cld - movl$4, %ecx - rep + movsl + movsl + movsl movsl popl%esi popl%edi @@ -169,7 +167,6 @@ movl%esp, %ebp pushl %edi pushl %esi - subl$24, %esp movlw10, %eax movl%eax, t10 movlw20, %eax @@ -179,36 +176,34 @@ movl$t21, %edi movl$w21, %esi cld - movl$2, %ecx - rep + movsl movsl movsb movl$t22, %edi movl$w22, %esi - movb$2, %cl - rep + movsl movsl movsw movl$t23, %edi movl$w23, %esi - movb$2, %cl - rep + movsl movsl movsw movsb movl$t30, %edi movl$w30, %esi - movb$3, %cl - rep + movsl + movsl movsl movl$t40, %edi movl$w40, %esi - movb$4, %cl - rep + movsl + movsl + movsl movsl movl$t50, %edi movl$w50, %esi - movb$5, %cl + movl$5, %ecx rep movsl movl$t60, %edi @@ -216,7 +211,6 @@ movb$6, %cl rep movsl - addl$24, %esp popl%esi popl%edi leave -- http://gcc.gnu.org/bugzilla/show_bug.cgi?id=21329
[Bug rtl-optimization/21329] optimize i386 block copy
--- Additional Comments From vda at port dot imtp dot ilyichevsk dot odessa dot ua 2005-05-02 09:10 --- BTW, see above comment: gcc -O2 allocated 24 bytes on stack and never uset them. ?! Now, unoptimized compilation comparison: --- t.s Mon May 2 11:41:20 2005 +++ t-new.s Mon May 2 11:39:40 2005 @@ -32,8 +32,8 @@ movl$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
