Add FMF to vector ops for phi

[mcberg2017]

Summary

Small amendment to handle vector cases for D67564.

[bogner]

Seems obviously correct to me.

[cameron.mcinally]

lib/Bitcode/Reader/BitcodeReader.cpp

4645

Would isFPOrFPVectorTy() be easier to read?

[spatel]

LGTM.

Note that @reames suggested that we should publicize the previous patch to make sure there were no known unintended consequences from this change, so:
http://lists.llvm.org/pipermail/llvm-dev/2019-September/135444.html

And I agree that we want to give everyone a chance to think about it, so I haven't proposed any dependent patches (and AFAIK, nobody else has yet either).

Assuming the change stays, I think we can build on it to solve bugs like:
https://bugs.llvm.org/show_bug.cgi?id=35607
https://bugs.llvm.org/show_bug.cgi?id=39535

[efriedma]

It looks like llvm-commits wasn't CC'ed, somehow.

lib/Bitcode/Reader/BitcodeReader.cpp

case bitc::FUNC_CODE_INST_PHI: { // PHI: [ty, val0,bb0, ...]
       Type *Ty = flattenPointerTypes(FullTy);
       if (!Ty)
         return error("Invalid record");
 
       // Phi arguments are pairs of records of [value, basic block].
       // There is an optional final record for fast-math-flags if this phi has a
       // floating-point type.
       size_t NumArgs = (Record.size() - 1) / 2;
-      if ((Record.size() - 1) % 2 == 1 && !Ty->isFloatingPointTy())
+      if ((Record.size() - 1) % 2 == 1 &&
+          !Ty->getScalarType()->isFloatingPointTy())
         return error("Invalid record");
 
       PHINode *PN = PHINode::Create(Ty, NumArgs);
       InstructionList.push_back(PN);
 
       for (unsigned i = 0; i != NumArgs; i++) {
         Value *V;
         // With the new function encoding, it is possible that operands have

test/Bitcode/compatibility.ll

exit:
   ; CHECK: %p.contract = phi contract half [ %h1, %L1 ], [ %h2, %L2 ]
   %p.nsz.reassoc = phi reassoc nsz float [ %f1, %L1 ], [ %f2, %L2 ]
   ; CHECK: %p.nsz.reassoc = phi reassoc nsz float [ %f1, %L1 ], [ %f2, %L2 ]
   %p.fast = phi fast half [ %h2, %L1 ], [ %h1, %L2 ]
   ; CHECK: %p.fast = phi fast half [ %h2, %L1 ], [ %h1, %L2 ]
   ret void
 }
 
+define void @fastmathflags_vector_phi(i1 %cond, <4 x float> %f1, <4 x float> %f2, <2 x double> %d1, <2 x double> %d2, <8 x half> %h1, <8 x half> %h2) {
+entry:
+  br i1 %cond, label %L1, label %L2
+L1:
+  br label %exit
+L2:
+  br label %exit
+exit:
+  %p.nnan = phi nnan <4 x float> [ %f1, %L1 ], [ %f2, %L2 ]
+  ; CHECK: %p.nnan = phi nnan <4 x float> [ %f1, %L1 ], [ %f2, %L2 ]
+  %p.ninf = phi ninf <2 x double> [ %d1, %L1 ], [ %d2, %L2 ]
+  ; CHECK: %p.ninf = phi ninf <2 x double> [ %d1, %L1 ], [ %d2, %L2 ]
+  %p.contract = phi contract <8 x half> [ %h1, %L1 ], [ %h2, %L2 ]
+  ; CHECK: %p.contract = phi contract <8 x half> [ %h1, %L1 ], [ %h2, %L2 ]
+  %p.nsz.reassoc = phi reassoc nsz <4 x float> [ %f1, %L1 ], [ %f2, %L2 ]
+  ; CHECK: %p.nsz.reassoc = phi reassoc nsz <4 x float> [ %f1, %L1 ], [ %f2, %L2 ]
+  %p.fast = phi fast <8 x half> [ %h2, %L1 ], [ %h1, %L2 ]
+  ; CHECK: %p.fast = phi fast <8 x half> [ %h2, %L1 ], [ %h1, %L2 ]
+  ret void
+}
+
 ; Check various fast math flags and floating-point types on calls.
 
 declare float @fmf1()
 declare double @fmf2()
 declare <4 x double> @fmf3()
 
 ; CHECK-LABEL: fastMathFlagsForCalls(
 define void @fastMathFlagsForCalls(float %f, double %d1, <4 x double> %d2) {