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From: "b.grayson at samsung dot com" <gcc-bugzilla@gcc.gnu.org> To: gcc-bugs@gcc.gnu.org Subject: [Bug target/58623] New: lack of ldp/stp optimization Date: Fri, 04 Oct 2013 19:19:00 -0000 [thread overview] Message-ID: <bug-58623-4@http.gcc.gnu.org/bugzilla/> (raw) http://gcc.gnu.org/bugzilla/show_bug.cgi?id=58623 Bug ID: 58623 Summary: lack of ldp/stp optimization Product: gcc Version: 4.9.0 Status: UNCONFIRMED Severity: normal Priority: P3 Component: target Assignee: unassigned at gcc dot gnu.org Reporter: b.grayson at samsung dot com Target: AArch64 Build: 20130602 The following C code: long long a, b; int c, d; int foo() { return a+b; } int bar() { return c+d; } generates this assembly code under -O3 -fsection-anchors -fno-common: foo: adrp x1, .LANCHOR0 add x1, x1, :lo12:.LANCHOR0 ldr x2, [x1] ldr x0, [x1,8] add w0, w2, w0 ret bar: adrp x1, .LANCHOR0 add x1, x1, :lo12:.LANCHOR0 ldr w2, [x1,16] ldr w0, [x1,20] add w0, w2, w0 ret Note that the ldr x2 and ldr x0 could have been merged into an ldp, in foo(). Similarly, the ldr w2 and ldr w0 (32-bit loads) could have been merged into an ldp in bar(). The same optimization applies to stores as well. I am not sure if this would be handled by the proposed (but apparently not accepted) patch from March 2013: http://gcc.gnu.org/ml/gcc-patches/2013-03/msg01051.html
next reply other threads:[~2013-10-04 19:19 UTC|newest] Thread overview: 8+ messages / expand[flat|nested] mbox.gz Atom feed top 2013-10-04 19:19 b.grayson at samsung dot com [this message] 2013-10-28 0:28 ` [Bug target/58623] " pinskia at gcc dot gnu.org 2014-07-24 11:05 ` ramana at gcc dot gnu.org 2014-11-19 2:00 ` amker.cheng at gmail dot com 2014-12-11 12:10 ` ramana at gcc dot gnu.org 2014-12-12 3:32 ` amker at gcc dot gnu.org 2014-12-15 21:35 ` e.menezes at samsung dot com 2014-12-18 3:02 ` amker at gcc dot gnu.org
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