From: kernel mailz <kernelmailz@googlemail.com>
To: gcc-help@gcc.gnu.org, gcc-help-help@gcc.gnu.org, linuxppc-dev@ozlabs.org
Subject: Inline Assembly queries
Date: Sun, 28 Jun 2009 01:16:56 +0530 [thread overview]
Message-ID: <abe8a1fd0906271246q920124ard61422d9577e2d09@mail.gmail.com> (raw)
Hello All the gurus,
I've been fiddling my luck with gcc 4.3.2 inline assembly on powerpc
There are a few queries
1. asm volatile or simply asm produce the same assembly code.
Tried with a few examples but didnt find any difference by adding
volatile with asm
2. Use of "memory" and clobbered registers.
"memory" -
a. announce to the compiler that the memory has been modified
b. this instruction writes to some memory (other than a listed output)
and GCC shouldn=92t cache memory values in registers across this asm.
I tried with stw and stwcx instruction, adding "memory" has no effect.
Is there any example scenerio where gcc would generate different
assembly by adding / removing "memory" ?
-TZ
next reply other threads:[~2009-06-27 19:47 UTC|newest]
Thread overview: 13+ messages / expand[flat|nested] mbox.gz Atom feed top
2009-06-27 19:46 kernel mailz [this message]
[not found] ` <abe8a1fd0906271249k479e5a87gfe1ee9c02798a234@mail.gmail.com>
[not found] ` <m3ab3t4623.fsf@google.com>
2009-06-28 4:57 ` Inline Assembly queries kernel mailz
2009-06-29 15:49 ` kernel mailz
2009-06-29 19:27 ` Scott Wood
2009-06-30 5:27 ` kernel mailz
2009-06-30 10:41 ` Benjamin Herrenschmidt
2009-06-29 21:29 ` Ian Lance Taylor
2009-06-30 5:53 ` kernel mailz
2009-06-30 9:30 ` Andrew Haley
2009-06-30 9:52 ` Paul Mackerras
2009-06-29 15:57 ` David Howells
2009-06-29 21:27 ` Ian Lance Taylor
2009-06-30 10:43 ` Benjamin Herrenschmidt
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