Needed by https://github.com/llvm/llvm-project/pull/121958.
Correctly handle the case where the clamp is over the full range. This fixes an issue introduced in #121206.
A signed min-max clamp is the sequence of smin and smax intrinsics, which constrain a signed value into the range: smin <= value <= smax. The patch improves the calculation of KnownBits for a value subjected to the signed clamping.
When Sel(Cmp) are in different integer type,
From: (K and N mean width, K < N; a and b are src operands.)
bN = Ext(bK)
cond = Cmp(aN, bN)
aK = Trunc aN
retK = Sel(cond, aK, bK)
To:
bN = Ext(bK)
cond = Cmp(aN, bN)
retN = Sel(cond, aN, bN)
retK = Trunc retN
Though Sel's operands width becomes larger, the benefit
of making type width in Sel the same as Cmp, is for combing
to max/min intrinsics, and also better performance for SIMD
instructions.
References of correctness: https://alive2.llvm.org/ce/z/Y4Kegm
https://alive2.llvm.org/ce/z/qFtjtR
Reference of generated code comparision:
https://gcc.godbolt.org/z/o97svGvYM
https://gcc.godbolt.org/z/59Ynj91ov
With the introduction of CmpPredicate in 51a895a (IR: introduce struct with CmpInst::Predicate and samesign), PatternMatch is one of the first key pieces of infrastructure that must be updated to match a CmpInst respecting samesign information. Implement this change to Cmp-matchers. This is a preparatory step in migrating the codebase over to CmpPredicate. Since we no functional changes are desired at this stage, we have chosen not to migrate CmpPredicate::operator==(CmpPredicate) calls to use CmpPredicate::getMatching(), as that would have visible impact on tests that are not yet written: instead, we call CmpPredicate::operator==(Predicate), preserving the old behavior, while also inserting a few FIXME comments for follow-ups.
After https://github.com/llvm/llvm-project/pull/118257, we may call `computeKnownFPClassFromCond` with unrelated conditions. Then miscompilations may occur due to a lack of operand checks. This bug was introduced by https://github.com/llvm/llvm-project/commit/d2404ea6ced5fce9442260bde08a02d607fdd50d and https://github.com/llvm/llvm-project/pull/80740. However, the miscompilation couldn't have happened before https://github.com/llvm/llvm-project/pull/118257, because we only added related conditions to `DomConditionCache/AssumptionCache`. Fix the miscompilation reported in https://github.com/llvm/llvm-project/pull/118257#issuecomment-2536182166.
Introduce llvm::CmpPredicate, an abstraction over a floating-point predicate, and a pack of an integer predicate with samesign information, in order to ease extending large portions of the codebase that take a CmpInst::Predicate to respect the samesign flag. We have chosen to demonstrate the utility of this new abstraction by migrating parts of ValueTracking, InstructionSimplify, and InstCombine from CmpInst::Predicate to llvm::CmpPredicate. There should be no functional changes, as we don't perform any extra optimizations with samesign in this patch, or use CmpPredicate::getMatching. The design approach taken by this patch allows for unaudited callers of APIs that take a llvm::CmpPredicate to silently drop the samesign information; it does not pose a correctness issue, and allows us to migrate the codebase piece-wise.
Fix a typo introduced by https://github.com/llvm/llvm-project/pull/83161. This patch also supports decomposition of and/or expressions in `computeKnownFPClassFromContext`. Compile-time improvement: http://llvm-compile-time-tracker.com/compare.php?from=688bb432c4b618de69a1d0e7807077a22f15762a&to=07493fc354b686f0aca79d6f817091a757bd7cd5&stat=instructions:u
Fixes #82414. General Proof: https://alive2.llvm.org/ce/z/ERjNs4 Proof for Tests: https://alive2.llvm.org/ce/z/K-934G This PR transforms `select` instructions of the form `select (Cmp X C1) (BOp X C2) C3` to `BOp (min/max X C1) C2` iff `C3 == BOp C1 C2`. This helps in eliminating a noop loop in https://github.com/rust-lang/rust/issues/123845 but does not improve optimizations.
This change is part of this proposal: https://discourse.llvm.org/t/rfc-all-the-math-intrinsics/78294 - Return true for atan2 from isTriviallyVectorizable - Add atan2 to VecFuncs.def for massv and accelerate libraries. - Add atan2 to hasOptimizedCodeGen - Add atan2 support in llvm/lib/Analysis/ValueTracking.cpp llvm::getIntrinsicForCallSite and update vectorization tests - Add atan2 name check to isLoweredToCall in llvm/include/llvm/Analysis/TargetTransformInfoImpl.h - Note: there's no test coverage for these names in isLoweredToCall, except that Transforms/TailCallElim/inf-recursion.ll is impacted by the "fabs" case Thanks to @jroelofs for the atan2 accelerate veclib and associated test additions, plus the hasOptimizedCodeGen addition. Part of: Implement the atan2 HLSL Function #70096.