diff options
| author | Hal Finkel <hfinkel@anl.gov> | 2012-08-28 02:10:27 +0000 |
|---|---|---|
| committer | Hal Finkel <hfinkel@anl.gov> | 2012-08-28 02:10:27 +0000 |
| commit | 82b3821208286aeb43f603fdac98832bd662dad9 (patch) | |
| tree | abb5ac4eea9e0f1504fb1f2f3ad847261a5179de /lib/Target/PowerPC/PPCInstrInfo.td | |
| parent | 97d047dec71cb37f31aac102cdc87b3dec0b1c46 (diff) | |
Eliminate redundant CR moves on PPC32.
The 32-bit ABI requires CR bit 6 to be set if the call has fp arguments and
unset if it doesn't. The solution up to now was to insert a MachineNode to
set/unset the CR bit, which produces a CR vreg. This vreg was then copied
into CR bit 6. When the register allocator saw a bunch of these in the same
function, it allocated the set/unset CR bit in some random CR register (1
extra instruction) and then emitted CR moves before every vararg function
call, rather than just setting and unsetting CR bit 6 directly before every
vararg function call. This patch instead inserts a PPCcrset/PPCcrunset
instruction which are then matched by a dedicated instruction pattern.
Patch by Tobias von Koch.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@162725 91177308-0d34-0410-b5e6-96231b3b80d8
Diffstat (limited to 'lib/Target/PowerPC/PPCInstrInfo.td')
| -rw-r--r-- | lib/Target/PowerPC/PPCInstrInfo.td | 16 |
1 files changed, 16 insertions, 0 deletions
diff --git a/lib/Target/PowerPC/PPCInstrInfo.td b/lib/Target/PowerPC/PPCInstrInfo.td index 20af16cea3..0230b4e795 100644 --- a/lib/Target/PowerPC/PPCInstrInfo.td +++ b/lib/Target/PowerPC/PPCInstrInfo.td @@ -155,6 +155,12 @@ def PPClbrx : SDNode<"PPCISD::LBRX", SDT_PPClbrx, def PPCstbrx : SDNode<"PPCISD::STBRX", SDT_PPCstbrx, [SDNPHasChain, SDNPMayStore]>; +// Instructions to set/unset CR bit 6 for SVR4 vararg calls +def PPCcr6set : SDNode<"PPCISD::CR6SET", SDTNone, + [SDNPHasChain, SDNPOptInGlue, SDNPOutGlue]>; +def PPCcr6unset : SDNode<"PPCISD::CR6UNSET", SDTNone, + [SDNPHasChain, SDNPOptInGlue, SDNPOutGlue]>; + // Instructions to support atomic operations def PPClarx : SDNode<"PPCISD::LARX", SDT_PPClarx, [SDNPHasChain, SDNPMayLoad]>; @@ -1145,6 +1151,16 @@ def CRUNSET: XLForm_1_ext<19, 193, (outs CRBITRC:$dst), (ins), "crxor $dst, $dst, $dst", BrCR, []>; +let Defs = [CR1EQ], CRD = 6 in { +def CR6SET : XLForm_1_ext<19, 289, (outs), (ins), + "creqv 6, 6, 6", BrCR, + [(PPCcr6set)]>; + +def CR6UNSET: XLForm_1_ext<19, 193, (outs), (ins), + "crxor 6, 6, 6", BrCR, + [(PPCcr6unset)]>; +} + // XFX-Form instructions. Instructions that deal with SPRs. // let Uses = [CTR] in { |