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From: "mikpe at it dot uu.se" <gcc-bugzilla@gcc.gnu.org>
To: gcc-bugs@gcc.gnu.org
Subject: [Bug target/51835] ARM EABI violation when passing arguments to helper floating functions like __aeabi_d2iz
Date: Sun, 05 Feb 2012 14:08:00 -0000	[thread overview]
Message-ID: <bug-51835-4-RpAT709PIM@http.gcc.gnu.org/bugzilla/> (raw)
In-Reply-To: <bug-51835-4@http.gcc.gnu.org/bugzilla/>

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=51835

Mikael Pettersson <mikpe at it dot uu.se> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
                 CC|                            |mikpe at it dot uu.se

--- Comment #5 from Mikael Pettersson <mikpe at it dot uu.se> 2012-02-05 14:07:49 UTC ---
(In reply to comment #2)
> This is only applicable to the 4.6 branch and trunk since support for the
> Cortex M4 wasn't added till 4.6. 
> 
> cheers
> Ramana

Maybe the Cortex M4 wasn't added until 4.6, but the other options are permitted
by 4.5 and I can easily get 4.5 to produce wrong-looking code.  With -O2
-mfloat-abi=hard -mfpu=fpv4-sp-d16 -march=armv7-a -marm I see the following
code generation difference between 4.5 and 4.6:

@@ -22,8 +22,9 @@
        @ frame_needed = 0, uses_anonymous_args = 0
        stmfd   sp!, {r3, lr}
        bl      __aeabi_f2d
+       fmrrd   r0, r1, d0
        bl      __aeabi_d2iz
        ldmfd   sp!, {r3, pc}
        .size   func, .-func
-       .ident  "GCC: (GNU) 4.5.4 20120126 (prerelease)"
+       .ident  "GCC: (GNU) 4.6.3 20120203 (prerelease)"
        .section        .note.GNU-stack,"",%progbits

Backporting r183734 from 4.6 to 4.5 makes 4.5 generate the same code as 4.6,
i.e., with the fmrrd between the two calls.


  parent reply	other threads:[~2012-02-05 14:08 UTC|newest]

Thread overview: 10+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2012-01-12  8:01 [Bug target/51835] New: " amker.cheng at gmail dot com
2012-01-16  9:50 ` [Bug target/51835] " rearnsha at gcc dot gnu.org
2012-01-19 23:08 ` ramana at gcc dot gnu.org
2012-01-30 18:05 ` jye2 at gcc dot gnu.org
2012-01-30 18:35 ` jye2 at gcc dot gnu.org
2012-02-05 14:08 ` mikpe at it dot uu.se [this message]
2012-02-06  5:52 ` amker.cheng at gmail dot com
2012-02-10  3:15 ` amker at gcc dot gnu.org
2012-02-14  7:43 ` amker at gcc dot gnu.org
2012-02-23  2:43 ` ramana at gcc dot gnu.org

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