Enable enableMultipleCopyHints() on X86.
Original Patch by @jonpa:
While enabling the mischeduler for SystemZ, it was discovered that for some reason a test needed one extra seemingly needless COPY (test/CodeGen/SystemZ/call-03.ll). The handling for that is resulted in this patch, which improves the register coalescing by providing not just one copy hint, but a sorted list of copy hints. On SystemZ, this gives ~12500 less register moves on SPEC, as well as marginally less spilling.
Instead of improving just the SystemZ backend, the improvement has been implemented in common-code (calculateSpillWeightAndHint(). This gives a lot of test failures, but since this should be a general improvement I hope that the involved targets will help and review the test updates.
Differential Revision: https://reviews.llvm.org/D38128
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@342578 91177308-0d34-0410-b5e6-96231b3b80d8
If the upper 32 bits of a 64 bit mask are all zeros, we have special isel patterns to use a 32-bit and instead of a 64-bit and by relying on the impliciting zeroing of 32 bit ops.
This patch teachs shrinkAndImmediate not to break that optimization.
Differential Revision: https://reviews.llvm.org/D42899
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@324249 91177308-0d34-0410-b5e6-96231b3b80d8
Try to reverse the constant-shrinking that happens in SimplifyDemandedBits()
for 'and' masks when it results in a smaller sign-extended immediate.
We are also able to detect dead 'and' ops here (the mask is all ones). In
that case, we replace and return without selecting the 'and'.
Other targets might want to share some of this logic by enabling this under a
target hook, but I didn't see diffs for simple cases with PowerPC or AArch64,
so they may already have some specialized logic for this kind of thing or have
different needs.
This should solve PR35907:
https://bugs.llvm.org/show_bug.cgi?id=35907
Differential Revision: https://reviews.llvm.org/D42088
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@322957 91177308-0d34-0410-b5e6-96231b3b80d8
`llc -march` is problematic because it only switches the target
architecture, but leaves the operating system unchanged. This
occasionally leads to indeterministic tests because the OS from
LLVM_DEFAULT_TARGET_TRIPLE is used.
However we can simply always use `llc -mtriple` instead. This changes
all the tests to do this to avoid people using -march when they copy and
paste parts of tests.
See also the discussion in https://reviews.llvm.org/D35287
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@309774 91177308-0d34-0410-b5e6-96231b3b80d8
We can set additional bits in a mask given that we know the other
operand of an AND already has some bits set to zero. This can be more
efficient if doing so allows us to use an instruction which implicitly
sign extends the immediate.
This fixes PR24085.
Differential Revision: http://reviews.llvm.org/D11289
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@245169 91177308-0d34-0410-b5e6-96231b3b80d8
Previously the patterns didn't have high enough priority and we would only use the GR32 form if the only the upper 32 or 56 bits were zero.
Fixes PR23100.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@234075 91177308-0d34-0410-b5e6-96231b3b80d8
The potential DAGCombine which enforces this more generally messes up some other very fragile patterns, so I'm leaving that alone, at least for now.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@132809 91177308-0d34-0410-b5e6-96231b3b80d8
Simon Pilgrim