FP128 values are passed in xmm registers so should be asssociated
with an SSE feature rather than MMX which uses a different set
of registers.
llc enables sse1 and sse2 by default with x86_64. But does not
enable mmx. Clang enables all 3 features by default.
I've tried to add command lines to test with -sse
where possible, but any test that returns a value in an xmm
register fails with a fatal error with -sse since we have no
defined ABI for that scenario.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@370682 91177308-0d34-0410-b5e6-96231b3b80d8
This is a follow on to D58632, with the same logic. Given a memory operation which needs ordering, but doesn't need to modify any particular address, prefer to use a locked stack op over an mfence.
Differential Revision: https://reviews.llvm.org/D61863
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@360649 91177308-0d34-0410-b5e6-96231b3b80d8
Summary: If we have SSE2 we can use a MOVQ to store 64-bits and avoid falling back to a cmpxchg8b loop. If its a seq_cst store we need to insert an mfence after the store.
Reviewers: spatel, RKSimon, reames, jfb, efriedma
Reviewed By: RKSimon
Subscribers: hiraditya, dexonsmith, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D60546
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@359368 91177308-0d34-0410-b5e6-96231b3b80d8
This patch adds patterns for turning bitcasted atomic load/store into movss/sd.
It also removes the pseudo instructions for atomic RMW fadd. Instead just adding isel patterns for folding an atomic load into addss/sd. And relying on the new movss/sd store pattern to handle the write part.
This also makes the fadd patterns use VEX and EVEX instructions when AVX or AVX512F are enabled.
Differential Revision: https://reviews.llvm.org/D60394
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@358215 91177308-0d34-0410-b5e6-96231b3b80d8
With correct test checks this time.
If we have X87, but not SSE2 we can atomicaly load an i64 value into the significand of an 80-bit extended precision x87 register using fild. We can then use a fist instruction to convert it back to an i64 integ
This matches what gcc and icc do for this case and removes an existing FIXME.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@358214 91177308-0d34-0410-b5e6-96231b3b80d8
If we have X87, but not SSE2 we can atomicaly load an i64 value into the significand of an 80-bit extended precision x87 register using fild. We can then use a fist instruction to convert it back to an i64 integer and store it to a stack temporary. From there we can do two 32-bit loads to get the value into integer registers without worrying about atomicness.
This matches what gcc and icc do for this case and removes an existing FIXME.
Differential Revision: https://reviews.llvm.org/D60156
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@358211 91177308-0d34-0410-b5e6-96231b3b80d8
We used a lock cmpxchg8b to do i64 atomic loads. But if we have SSE2 we can do better and use a plain movq to do the load instead.
I tried to just use an f64 atomic load and add isel patterns to MOVSD(which the domain fixing pass can turn to MOVQ), but the atomic_load SDNode in TargetSelectionDAG.td requires the type to be integer.
So I've emitted VZEXT_LOAD instead which should be selected by isel to a MOVQ. Hopefully we don't need a specific atomic flavor of this. I kept the memory operand from the original AtomicSDNode. I wasn't sure if I might need to set the MOVolatile flag?
I've left some FIXMEs for improvements we can do without SSE2.
Differential Revision: https://reviews.llvm.org/D59679
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@356807 91177308-0d34-0410-b5e6-96231b3b80d8
Building on the work done in D57601, now that we can distinguish between atomic and volatile memory accesses, go ahead and allow code motion of unordered atomics. As seen in the diffs, this allows much better folding of memory operations into using instructions. (Mostly done by the PeepholeOpt pass.)
Note: I have not reviewed all callers of hasOrderedMemoryRef since one of them - isSafeToMove - is very widely used. I'm relying on the documented semantics of each method to judge correctness.
Differential Revision: https://reviews.llvm.org/D59345
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@356170 91177308-0d34-0410-b5e6-96231b3b80d8
At one point in time acquire implied mayLoad and mayStore as did release. Thus we needed separate pseudos that also carried that property. This appears to no longer be the case. I believe it was changed in 2012 with a comment saying that atomic memory accesses are marked volatile which preserves the ordering.
So from what I can tell we shouldn't need additional pseudos since they aren't carry any flags that are different from the normal instructions. The only thing I can think of is that we may consider them for load folding candidates in the peephole pass now where we didn't before. If that's important hopefully there's something in the memory operand we can check to prevent the folding without relying on pseudo instructions.
Differential Revision: https://reviews.llvm.org/D50212
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@338925 91177308-0d34-0410-b5e6-96231b3b80d8
We were just completely ignoring the types when determining whether we could
safely emit a libcall as a tail call. This is clearly wrong.
Theoretically, we could dig deeper looking for incidental matches (much like
the generic code in Analysis.cpp does), but it's probably not worth it for the
few libcalls that exist.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@264084 91177308-0d34-0410-b5e6-96231b3b80d8
This patch allows atomic loads and stores of floating point to be specified in the IR and adds an adapter to allow them to be lowered via existing backend support for bitcast-to-equivalent-integer idiom.
Previously, the only way to specify a atomic float operation was to bitcast the pointer to a i32, load the value as an i32, then bitcast to a float. At it's most basic, this patch simply moves this expansion step to the point we start lowering to the backend.
This patch does not add canonicalization rules to convert the bitcast idioms to the appropriate atomic loads. I plan to do that in the future, but for now, let's simply add the support. I'd like to get instruction selection working through at least one backend (x86-64) without the bitcast conversion before canonicalizing into this form.
Similarly, I haven't yet added the target hooks to opt out of the lowering step I added to AtomicExpand. I figured it would more sense to add those once at least one backend (x86) was ready to actually opt out.
As you can see from the included tests, the generated code quality is not great. I plan on submitting some patches to fix this, but help from others along that line would be very welcome. I'm not super familiar with the backend and my ramp up time may be material.
Differential Revision: http://reviews.llvm.org/D15471
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@255737 91177308-0d34-0410-b5e6-96231b3b80d8
Craig Topper