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| author | Jakob Stoklund Olesen <stoklund@2pi.dk> | 2011-03-09 19:27:06 +0000 |
|---|---|---|
| committer | Jakob Stoklund Olesen <stoklund@2pi.dk> | 2011-03-09 19:27:06 +0000 |
| commit | d0db705256b616b6fa89bb8c0827d06d73d0ce44 (patch) | |
| tree | 338fb69e8eb901a42328174c89761d5baec73e46 /llvm/lib/CodeGen | |
| parent | 456e104c13cb1041582cfe68cd242dd72d27bded (diff) | |
| download | bcm5719-llvm-d0db705256b616b6fa89bb8c0827d06d73d0ce44.tar.gz bcm5719-llvm-d0db705256b616b6fa89bb8c0827d06d73d0ce44.zip | |
Make physreg coalescing independent on the number of uses of the virtual register.
The damage done by physreg coalescing only depends on the number of instructions
the extended physreg live range covers. This fixes PR9438.
The heuristic is still luck-based, and physreg coalescing really should be
disabled completely. We need a register allocator with better hinting support
before that is possible.
Convert a test to FileCheck and force spilling by inserting an extra call. The
previous spilling behavior was dependent on misguided physreg coalescing
decisions.
llvm-svn: 127351
Diffstat (limited to 'llvm/lib/CodeGen')
| -rw-r--r-- | llvm/lib/CodeGen/SimpleRegisterCoalescing.cpp | 4 |
1 files changed, 1 insertions, 3 deletions
diff --git a/llvm/lib/CodeGen/SimpleRegisterCoalescing.cpp b/llvm/lib/CodeGen/SimpleRegisterCoalescing.cpp index 74898c210a4..8a102702ef3 100644 --- a/llvm/lib/CodeGen/SimpleRegisterCoalescing.cpp +++ b/llvm/lib/CodeGen/SimpleRegisterCoalescing.cpp @@ -1038,9 +1038,7 @@ bool SimpleRegisterCoalescing::JoinCopy(CopyRec &TheCopy, bool &Again) { const TargetRegisterClass *RC = mri_->getRegClass(CP.getSrcReg()); unsigned Threshold = allocatableRCRegs_[RC].count() * 2; unsigned Length = li_->getApproximateInstructionCount(JoinVInt); - if (Length > Threshold && - std::distance(mri_->use_nodbg_begin(CP.getSrcReg()), - mri_->use_nodbg_end()) * Threshold < Length) { + if (Length > Threshold) { // Before giving up coalescing, if definition of source is defined by // trivial computation, try rematerializing it. if (!CP.isFlipped() && |
