diff options
| author | Hal Finkel <hfinkel@anl.gov> | 2013-03-26 18:56:54 +0000 |
|---|---|---|
| committer | Hal Finkel <hfinkel@anl.gov> | 2013-03-26 18:56:54 +0000 |
| commit | 8846129f6eb58982a2cac22306c8c9b586084475 (patch) | |
| tree | bd24c433fd6347a3238caebe8f4636ed48b80725 /lib/CodeGen/RegisterScavenging.cpp | |
| parent | b4f60e9f772de7152a0880d84c5ef511f6d2c642 (diff) | |
Update PEI's virtual-register-based scavenging to support multiple simultaneous mappings
The previous algorithm could not deal properly with scavenging multiple virtual
registers because it kept only one live virtual -> physical mapping (and
iterated through operands in order). Now we don't maintain a current mapping,
but rather use replaceRegWith to completely remove the virtual register as
soon as the mapping is established.
In order to allow the register scavenger to return a physical register killed
by an instruction for definition by that same instruction, we now call
RS->forward(I) prior to eliminating virtual registers defined in I. This
requires a minor update to forward to ignore virtual registers.
These new features will be tested in forthcoming commits.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@178058 91177308-0d34-0410-b5e6-96231b3b80d8
Diffstat (limited to 'lib/CodeGen/RegisterScavenging.cpp')
| -rw-r--r-- | lib/CodeGen/RegisterScavenging.cpp | 4 |
1 files changed, 2 insertions, 2 deletions
diff --git a/lib/CodeGen/RegisterScavenging.cpp b/lib/CodeGen/RegisterScavenging.cpp index b54bf7ddf7..4c85644e1a 100644 --- a/lib/CodeGen/RegisterScavenging.cpp +++ b/lib/CodeGen/RegisterScavenging.cpp @@ -150,7 +150,7 @@ void RegScavenger::forward() { if (!MO.isReg()) continue; unsigned Reg = MO.getReg(); - if (!Reg || isReserved(Reg)) + if (!Reg || TargetRegisterInfo::isVirtualRegister(Reg) || isReserved(Reg)) continue; if (MO.isUse()) { @@ -175,7 +175,7 @@ void RegScavenger::forward() { if (!MO.isReg()) continue; unsigned Reg = MO.getReg(); - if (!Reg || isReserved(Reg)) + if (!Reg || TargetRegisterInfo::isVirtualRegister(Reg) || isReserved(Reg)) continue; if (MO.isUse()) { if (MO.isUndef()) |