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path: root/test/CodeGen/ARM/coalesce-subregs.ll
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* Avoid rewriting instructions twice.Jakob Stoklund Olesen2012-11-29
| | | | | | | | | This could cause miscompilations in targets where sub-register composition is not always idempotent (ARM). <rdar://problem/12758887> git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@168837 91177308-0d34-0410-b5e6-96231b3b80d8
* Cleanup the main RegisterCoalescer loop.Andrew Trick2012-11-13
| | | | | | Block priorities still apply outside loops. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@167793 91177308-0d34-0410-b5e6-96231b3b80d8
* Completely disallow partial copies in adjustCopiesBackFrom().Jakob Stoklund Olesen2012-10-29
| | | | | | | | | | | | Partial copies can show up even when CoalescerPair.isPartial() returns false. For example: %vreg24:dsub_0<def> = COPY %vreg31:dsub_0; QPR:%vreg24,%vreg31 Such a partial-partial copy is not good enough for the transformation adjustCopiesBackFrom() needs to do. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@166944 91177308-0d34-0410-b5e6-96231b3b80d8
* Revert r166046 "Switch back to the old coalescer for now to fix the 32 bit bit"Jakob Stoklund Olesen2012-10-16
| | | | | | A fix for PR14098, including the test case is in the next commit. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@166067 91177308-0d34-0410-b5e6-96231b3b80d8
* Switch back to the old coalescer for now to fix the 32 bit bitRafael Espindola2012-10-16
| | | | | | llvm+clang+compiler-rt bootstrap. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@166046 91177308-0d34-0410-b5e6-96231b3b80d8
* Drop <def,dead> flags when merging into an unused lane.Jakob Stoklund Olesen2012-10-13
| | | | | | | | | | | | The new coalescer can merge a dead def into an unused lane of an otherwise live vector register. Clear the <dead> flag when that happens since the flag refers to the full virtual register which is still live after the partial dead def. This fixes PR14079. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@165877 91177308-0d34-0410-b5e6-96231b3b80d8
* Allow for loops in LiveIntervals::pruneValue().Jakob Stoklund Olesen2012-10-13
| | | | | | | | | | | | | | It is possible that the live range of the value being pruned loops back into the kill MBB where the search started. When that happens, make sure that the beginning of KillMBB is also pruned. Instead of starting a DFS at KillMBB and skipping the root of the search, start a DFS at each KillMBB successor, and allow the search to loop back to KillMBB. This fixes PR14078. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@165872 91177308-0d34-0410-b5e6-96231b3b80d8
* Make sure the whole live range is covered when values are pruned twice.Jakob Stoklund Olesen2012-10-02
| | | | | | | | | | | | | | | | | | | | | | | | JoinVals::pruneValues() calls LIS->pruneValue() to avoid conflicts when overlapping two different values. This produces a set of live range end points that are used to reconstruct the live range (with SSA update) after joining the two registers. When a value is pruned twice, the set of end points was insufficient: v1 = DEF v1 = REPLACE1 v1 = REPLACE2 KILL v1 The end point at KILL would only reconstruct the live range from REPLACE2 to KILL, leaving the range REPLACE1-REPLACE2 dead. Add REPLACE2 as an end point in this case so the full live range is reconstructed. This fixes PR13999. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@165056 91177308-0d34-0410-b5e6-96231b3b80d8
* Ignore PHI-defs for -new-coalescer interference checks.Jakob Stoklund Olesen2012-09-20
| | | | | | | | A PHI can't create interference on its own. If two live ranges interfere at a PHI, they must also interfere when leaving one of the PHI predecessors. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@164330 91177308-0d34-0410-b5e6-96231b3b80d8
* Resolve conflicts involving dead vector lanes for -new-coalescer.Jakob Stoklund Olesen2012-09-19
| | | | | | | | | | | | | | | | | | | | | A common coalescing conflict in vector code is lane insertion: %dst = FOO %src = BAR %dst:ssub0 = COPY %src The live range of %src interferes with the ssub0 lane of %dst, but that lane is never read after %src would have clobbered it. That makes it safe to merge the live ranges and eliminate the COPY: %dst = FOO %dst:ssub0 = BAR This patch teaches the new coalescer to resolve conflicts where dead vector lanes would be clobbered, at least as long as the clobbered vector lanes don't escape the basic block. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@164250 91177308-0d34-0410-b5e6-96231b3b80d8
* Merge into undefined lanes under -new-coalescer.Jakob Stoklund Olesen2012-09-17
| | | | | | | | | | | | | | | | | Add LIS::pruneValue() and extendToIndices(). These two functions are used by the register coalescer when merging two live ranges requires more than a trivial value mapping as supported by LiveInterval::join(). The pruneValue() function can remove the part of a value number that is going to conflict in join(). Afterwards, extendToIndices can restore the live range, using any new dominating value numbers and updating the SSA form. Use this complex value mapping to support merging a register into a vector lane that has a conflicting value, but the clobbered lane is undef. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@164074 91177308-0d34-0410-b5e6-96231b3b80d8
* Enable sub-sub-register copy coalescing.Jakob Stoklund Olesen2012-05-15
It is now possible to coalesce weird skewed sub-register copies by picking a super-register class larger than both original registers. The included test case produces code like this: vld2.32 {d16, d17, d18, d19}, [r0]! vst2.32 {d18, d19, d20, d21}, [r0] We still perform interference checking as if it were a normal full copy join, so this is still quite conservative. In particular, the f1 and f2 functions in the included test case still have remaining copies because of false interference. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@156878 91177308-0d34-0410-b5e6-96231b3b80d8