Assertion `!OpInfo.AssignedRegs.Regs.empty() && "Couldn't allocate input reg!"' failed.

[llvmbot]

Bugzilla Link	2511
Resolution	DUPLICATE
Resolved on	Oct 16, 2008 00:44
Version	trunk
OS	Linux
Attachments	foo.bc
Reporter	LLVM Bugzilla Contributor

Extended Description

llc foo.bc results in an assertion in the register allocator (x86 backend).

[llvmbot]

assigned to @lattner

[llvmbot]

My inline asm foo is weak.

i32 (i64, i64*, i32, i32)* asm sideeffect "1:\09movl %eax,0($2)\0A2:\09movl %edx,4($2)\0A3:\0A.section .fixup,\22ax\22\0A4:\09movl $3,$0\0A\09jmp 3b\0A.previous\0A .section __ex_table,\22a\22\0A
.balign 4 \0A .long 1b,4b\0A .previous\0A .section __ex_table,\22a\22\0A .balign 4 \0A .long 2b,4b\0A .previous\0A", "=r,A,r,i,0,{dirflag},{fpsr},~{flags}"

The failing constraint is 'A', in operand is i64 Constant 0. Chris, can you make sense of this?

[lattner]

It's easier to read if you ignore the asm string:

i32 (i64, i64*, i32, i32)* asm sideeffect "", "=r,A,r,i,0,{dirflag},{fpsr},~{flags}"

This says the result is in any 'r', the first input i64 goes in EAX/EDX, the pointer goes in any 'r', the next arg must be an immediate, and the last arg has to be in the same reg the result returns.

[lattner]

*** This bug has been marked as a duplicate of bug #2151 ***