[llvm] Fix mechanism propagating mangled names for TLI function mappings (PR #66656)

[via llvm-commits]

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@@ -23,860 +23,860 @@
 #define MASKED true
 
 #if !(defined(TLI_DEFINE_VECFUNC))
-#define TLI_DEFINE_VECFUNC(SCAL, VEC, VF) {SCAL, VEC, VF, NOMASK},
+#define TLI_DEFINE_VECFUNC(SCAL, VEC, VF, MANGLN) {SCAL, VEC, VF, NOMASK, MANGLN},
 #endif
 
 #if defined(TLI_DEFINE_ACCELERATE_VECFUNCS)
 // Accelerate framework's Vector Functions
 
 // Floating-Point Arithmetic and Auxiliary Functions
-TLI_DEFINE_VECFUNC("ceilf", "vceilf", FIXED(4))
-TLI_DEFINE_VECFUNC("fabsf", "vfabsf", FIXED(4))
-TLI_DEFINE_VECFUNC("llvm.fabs.f32", "vfabsf", FIXED(4))
-TLI_DEFINE_VECFUNC("floorf", "vfloorf", FIXED(4))
-TLI_DEFINE_VECFUNC("sqrtf", "vsqrtf", FIXED(4))
-TLI_DEFINE_VECFUNC("llvm.sqrt.f32", "vsqrtf", FIXED(4))
+TLI_DEFINE_VECFUNC("ceilf", "vceilf", FIXED(4), "_ZGV_LLVM_N4v_ceilf(vceilf)")
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JolantaJensen wrote:

I'm afraid I cannot shorten the mangled name removing the optional part.
If I do I'll crash in VFABI::setVectorVariantNames()  with
assert(VI && "Cannot add an invalid VFABI name.").
The culprit is the code below. VectorName will only be changed if there
is an optional part. For LLVM isa this causes a std::nullopt return
because the VectorName is unchanged and equals OriginalName.

std::optional<VFInfo> VFABI::tryDemangleForVFABI(StringRef MangledName,
                                                 const Module &M) {
  const StringRef OriginalName = MangledName;
  StringRef VectorName = MangledName;
...
  // Reduce MangledName to [(<redirection>)].
  MangledName = MangledName.ltrim(ScalarName);
  // Find the optional custom name redirection.
  if (MangledName.consume_front("(")) {
    if (!MangledName.consume_back(")"))
      return std::nullopt;
    // Update the vector variant with the one specified by the user.
    VectorName = MangledName;
    // If the vector name is missing, bail out.
    if (VectorName.empty())
      return std::nullopt;
  }
  // LLVM internal mapping via the TargetLibraryInfo (TLI) must be
  // redirected to an existing name.
  if (ISA == VFISAKind::LLVM && VectorName == OriginalName)
    return std::nullopt;

Sorry for not formatting the above as code but this removes all line breaks for me.

https://github.com/llvm/llvm-project/pull/66656