llvm-6502

mirror of https://github.com/c64scene-ar/llvm-6502.git synced 2025-01-21 19:32:16 +00:00

History

Jakob Stoklund Olesen 201f2463a7 Don't treat a partial <def,undef> operand as a read.

Normally, a partial register def is treated as reading the
super-register unless it also defines the full register like this:

  %vreg110:sub_32bit<def> = COPY %vreg77:sub_32bit, %vreg110<imp-def>

This patch also uses the <undef> flag on partial defs to recognize
non-reading operands:

  %vreg110:sub_32bit<def,undef> = COPY %vreg77:sub_32bit

This fixes a subtle bug in RegisterCoalescer where LIS->shrinkToUses
would treat a coalesced copy as still reading the register, extending
the live range artificially.

My test case only works when I disable DCE so a dead copy is left for
RegisterCoalescer, so I am not including it.

<rdar://problem/9967101>

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@138018 91177308-0d34-0410-b5e6-96231b3b80d8

2011-08-19 00:30:17 +00:00

Analysis

There is no need to add file as context for subroutine type. The subroutine type does not need any context.

2011-08-18 23:50:57 +00:00