ValueTracking: Revert noundef checks in computeKnownFPClass for fmul/fma
This functionally reverts fd5cfcc41311c6287e9dc408b8aae499501660e1 and
35ce17b6f6ca5dd321af8e6763554b10824e4ac4.
This was correct and necessary, but is causing performance regressions
since isGuaranteedNotToBeUndef is apparently not smart enough to detect
through recurrences. Revert this for the release branch.
Also the test coverage was inadequate for the fma case, so add a new
case which changes with and without the check.
[GlobalISel] Insert bitcast instead of register replacement when types don't match. (#177397)
Cases like the newly added test with the vector types currently hit
```Assertion `canReplaceReg(OldReg, Replacement, MRI) && \"Cannot
replace register?\"' failed."``` because source and destination
registers have mismatching types. Apart from the assertion, it also
fails when using `--verify-machineinstrs`. This PR adds a bitcast in
those cases.
[DAG] Enable bitcast STLF for Constant/Undef (#172523)
This patch introduces support for Store-to-Load Forwarding (STLF) in
`DAGCombiner::ForwardStoreValueToDirectLoad` when the store and load
have **different types but equal memory size** (e.g., storing an `i32`
then loading a `float` from the same location).
### What this patch does:
**Enables Optimization:** It allows for the safe forwarding of the
stored value as a Bitcast when the value is:
* A **Constant** (`ConstantSDNode`, `ConstantFPSDNode`,
`ConstantPoolSDNode`).
* **Undef**.
* And the memory sizes (`LdMemSize` == `StMemSize`) match.
### Scope and Next Steps:
This patch **only implements forwarding for constant and undef values
that has the same memory size** so far.
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[MemCpyOpt] Extend `performMemCpyToMemSetOptzn` to partially memset'd region
While doing memset-to-memcpy forwarding, take into account memset
that covers memory regions from a given offset, and the leading
bytes of such a region are undef.
Fixes: https://github.com/llvm/llvm-project/issues/172326.
[clang][bytecode] Clean up `interp::Function` parameter handling (#178621)
Replace the multiple data structures with a vector + a map holding all
`ParamDescriptor`s. Update docs.
Add test for amdgcn.if/else uniformity analysis
This test documents the current behavior where both outputs of
amdgcn.if and amdgcn.else are marked as divergent. The second
output (exec mask) should be uniform.
[Driver][Frontend] Add -f[no-]ms-anonymous-structs flag to control Microsoft anonymous struct/union extension (#176551)
Add a Clang driver option -fms-anonymous-structs and
-fno-ms-anonymous-structs
to enable or disable Microsoft anonymous struct/union support
independently of -fms-extensions.
**Motivation**:
- On some platforms (e.g. AIX), enabling `-fms-extensions` can conflict
with system headers (such as usage of `__ptr32`).
- Some codebases rely specifically on Microsoft anonymous struct/union
behavior without requiring other Microsoft extensions.
This change allows users to selectively enable the anonymous
struct/union
extension at the driver level without enabling full Microsoft
compatibility
mode.
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