[ValueTracking] Fix computeKnownFPClass with canonicalize

[piotr]

Summary

Update code that assumes llvm.canonicalize only handles scalars,
by adding a call to getScalarType().
This is fine, as the intrinsic is trivially vectorizable.

Introduced in D147870, and uncovered by D148065.

llvm/lib/Analysis/ValueTracking.cpp

if (const IntrinsicInst *II = dyn_cast<IntrinsicInst>(Op)) {
       case Intrinsic::canonicalize: {
         computeKnownFPClass(II->getArgOperand(0), DemandedElts,
                             InterestedClasses, Known, Depth + 1, Q, TLI);
         // Canonicalize is guaranteed to quiet signaling nans.
         Known.knownNot(fcSNan);
 
         // If the parent function flushes denormals, the canonical output cannot
         // be a denormal.
-        const fltSemantics &FPType = II->getType()->getFltSemantics();
+        const fltSemantics &FPType =
+            II->getType()->getScalarType()->getFltSemantics();
         DenormalMode DenormMode = II->getFunction()->getDenormalMode(FPType);
         if (DenormMode.inputsAreZero() || DenormMode.outputsAreZero())
           Known.knownNot(fcSubnormal);
 
         if (DenormMode.Input == DenormalMode::PositiveZero ||
             (DenormMode.Output == DenormalMode::PositiveZero &&
              DenormMode.Input == DenormalMode::IEEE))
           Known.knownNot(fcNegZero);

llvm/test/Transforms/InstCombine/canonicalize.ll

 ; CHECK-NEXT:    [[CMP:%.*]] = fcmp uno float [[X:%.*]], 0.000000e+00
 ; CHECK-NEXT:    ret i1 [[CMP]]
 ;
   %canon.x = call float @llvm.canonicalize.f32(float %x)
   %cmp = fcmp uno float %canon.x, %x
   ret i1 %cmp
 }
 
+; --------------------------------------------------------------------
+; Others
+; --------------------------------------------------------------------
+
+; Regression test checking that the vector version of llvm.canonicalize works.
+define <2 x i1> @vec_canonicalize_with_fpclass(<2 x float> %x) {
+; CHECK-LABEL: @vec_canonicalize_with_fpclass(
+; CHECK-NEXT:    ret <2 x i1> zeroinitializer
+;
+  %canon = call <2 x float> @llvm.canonicalize.v2f32(<2 x float> %x)
+  %fpclass = call <2 x i1> @llvm.is.fpclass.v2f32(<2 x float> %canon, i32 1)
+  ret <2 x i1> %fpclass
+}
+
 declare float @llvm.canonicalize.f32(float)
 declare <2 x float> @llvm.canonicalize.v2f32(<2 x float>)
+declare <2 x i1> @llvm.is.fpclass.v2f32(<2 x float>, i32 immarg)