LLVM Bugzilla is read-only and represents the historical archive of all LLVM issues filled before November 26, 2021. Use github to submit LLVM bugs

Bug 1029 - Couldn't allocate output reg for contraint 'r' (AMD64)
Summary: Couldn't allocate output reg for contraint 'r' (AMD64)
Status: RESOLVED FIXED
Alias: None
Product: libraries
Classification: Unclassified
Component: Backend: X86 (show other bugs)
Version: 1.9
Hardware: Other Linux
: P normal
Assignee: Unassigned LLVM Bugs
URL:
Keywords: compile-fail
Depends on:
Blocks:
 
Reported: 2006-12-01 11:50 PST by Rafael Ávila de Espíndola
Modified: 2010-02-22 12:54 PST (History)
1 user (show)

See Also:
Fixed By Commit(s):

Attachments
test.ll (365 bytes, text/plain)
2006-12-04 06:18 PST, Rafael Ávila de Espíndola 		Details
add the 64bit registers for the "r" constraint (1007 bytes, patch)
2006-12-04 07:34 PST, Rafael Ávila de Espíndola 		Details
Add an attachment (proposed patch, testcase, etc.)

Note You need to log in before you can comment on or make changes to this bug.
Description Rafael Ávila de Espíndola 2006-12-01 11:50:00 PST 
the code
------------------------------------
void
frame_dummy (void)
{

        void (*register_classes) (void *) = 0;
      __asm ("" : "+r" (register_classes));
}
------------------------------------
produces the following error:
---------------------------------------------
Couldn't allocate output reg for contraint 'r'!
---------------------------------------------
Comment 1 Rafael Ávila de Espíndola 2006-12-04 06:18:05 PST 
Created attachment 498 [details]
test.ll
Comment 2 Rafael Ávila de Espíndola 2006-12-04 07:05:33 PST 
setting a breakpoint in SelectionDAGLowering::GetRegistersForValue shows that 
ConstrCode is "r". The code seems to expect that a constraint is braced 
with "{}"....
Comment 3 Rafael Ávila de Espíndola 2006-12-04 07:34:16 PST 
Created attachment 499 [details]
add the 64bit registers for the "r" constraint
Comment 4 Chris Lattner 2006-12-04 16:39:22 PST 
Patch applied, thanks Rafael!

Patch here:
http://lists.cs.uiuc.edu/pipermail/llvm-commits/Week-of-Mon-20061204/040773.html

Testcase here: Regression/CodeGen/X86/x86-64-asm.ll

-Chris