[HardwareLoops] Add support for strictfp functions. (#84531)

This pass was adding new function calls without adding the strictfp
attribute as required by the rules laid out in the langref. With this
change a make check has 4-5 fewer failing tests with the Verifier
changes in D146845.

LangRef:
https://llvm.org/docs/LangRef.html#constrained-floating-point-intrinsics

Test failures found with "https://reviews.llvm.org/D146845".

Author: kpneal

llvm/lib/CodeGen/HardwareLoops.cpp

@@ -503,6 +503,8 @@ Value *HardwareLoop::InitLoopCount() {
 
 Value* HardwareLoop::InsertIterationSetup(Value *LoopCountInit) {
   IRBuilder<> Builder(BeginBB->getTerminator());
+  if (BeginBB->getParent()->getAttributes().hasFnAttr(Attribute::StrictFP))
+    Builder.setIsFPConstrained(true);
   Type *Ty = LoopCountInit->getType();
   bool UsePhi = UsePHICounter || Opts.ForcePhi;
   Intrinsic::ID ID = UseLoopGuard
@@ -535,6 +537,9 @@ Value* HardwareLoop::InsertIterationSetup(Value *LoopCountInit) {
 
 void HardwareLoop::InsertLoopDec() {
   IRBuilder<> CondBuilder(ExitBranch);
+  if (ExitBranch->getParent()->getParent()->getAttributes().hasFnAttr(
+          Attribute::StrictFP))
+    CondBuilder.setIsFPConstrained(true);
 
   Function *DecFunc =
     Intrinsic::getDeclaration(M, Intrinsic::loop_decrement,
@@ -557,6 +562,9 @@ void HardwareLoop::InsertLoopDec() {
 
 Instruction* HardwareLoop::InsertLoopRegDec(Value *EltsRem) {
   IRBuilder<> CondBuilder(ExitBranch);
+  if (ExitBranch->getParent()->getParent()->getAttributes().hasFnAttr(
+          Attribute::StrictFP))
+    CondBuilder.setIsFPConstrained(true);
 
   Function *DecFunc =
       Intrinsic::getDeclaration(M, Intrinsic::loop_decrement_reg,