533802 - x64 version of asm_load64 doesn't attempt to use FpRegs for 64-bit loads

Status: RESOLVED INVALID

(Core Graveyard :: Nanojit, defect)

Description

[Steven Johnson]

It calls regalloc_load to get a register, which implicitly limits to GpRegs. We could trivially pass in a mask to allow FpRegs as well, allowing greater register utilization.

Quoth Edwin: "the risk is that if you load something that is later used as a pointer, then you have to move it to a GPR first. since you'll see the pointer-use first (bottom up), it wont be a problem when the uses are close together.  for spill/restore situations we may need a hint flag that a GPR is preferred."

So this probably needs some profiling at before such a patch can land.

Comment 1

[Edwin Smith]

now that LIR distinguishes quad from double, this is obsolete.