diff options
Diffstat (limited to 'lib/Target/X86/X86ISelLowering.h')
| -rw-r--r-- | lib/Target/X86/X86ISelLowering.h | 16 |
1 files changed, 16 insertions, 0 deletions
diff --git a/lib/Target/X86/X86ISelLowering.h b/lib/Target/X86/X86ISelLowering.h index f0b64992bf..af9466d8f8 100644 --- a/lib/Target/X86/X86ISelLowering.h +++ b/lib/Target/X86/X86ISelLowering.h @@ -370,4 +370,20 @@ namespace llvm { }; } +// FASTCC_NUM_INT_ARGS_INREGS - This is the max number of integer arguments +// to pass in registers. 0 is none, 1 is is "use EAX", 2 is "use EAX and +// EDX". Anything more is illegal. +// +// FIXME: The linscan register allocator currently has problem with +// coalescing. At the time of this writing, whenever it decides to coalesce +// a physreg with a virtreg, this increases the size of the physreg's live +// range, and the live range cannot ever be reduced. This causes problems if +// too many physregs are coaleced with virtregs, which can cause the register +// allocator to wedge itself. +// +// This code triggers this problem more often if we pass args in registers, +// so disable it until this is fixed. +// +#define FASTCC_NUM_INT_ARGS_INREGS 0 + #endif // X86ISELLOWERING_H |