[GlobalISel] Add IRTranslator support for @llvm.sqrt -> G_FSQRT

[paquette]

Summary

Follow-up commit to https://reviews.llvm.org/D57359.

This adds IRTranslator support for recognising a @llvm.sqrt intrinsic and translating it into a G_FSQRT.

[volkan]

LGTM

[paquette]

Thanks! Committed in r352670.

lib/CodeGen/GlobalISel/IRTranslator.cpp

MIRBuilder.buildInstr(TargetOpcode::G_FCOS)
         .addDef(getOrCreateVReg(CI))
         .addUse(getOrCreateVReg(*CI.getArgOperand(0)));
     return true;
   case Intrinsic::sin:
     MIRBuilder.buildInstr(TargetOpcode::G_FSIN)
         .addDef(getOrCreateVReg(CI))
         .addUse(getOrCreateVReg(*CI.getArgOperand(0)));
     return true;
+  case Intrinsic::sqrt:
+    MIRBuilder.buildInstr(TargetOpcode::G_FSQRT)
+        .addDef(getOrCreateVReg(CI))
+        .addUse(getOrCreateVReg(*CI.getArgOperand(0)));
+    return true;
   }
   return false;
 }
 
 bool IRTranslator::translateInlineAsm(const CallInst &CI,
                                       MachineIRBuilder &MIRBuilder) {
   const InlineAsm &IA = cast<InlineAsm>(*CI.getCalledValue());
   if (!IA.getConstraintString().empty())

test/CodeGen/AArch64/GlobalISel/arm64-irtranslator.ll

 
 declare float @llvm.sin.f32(float)
 define float @test_sin_f32(float %x) {
   ; CHECK-LABEL: name:            test_sin_f32
   ; CHECK: %{{[0-9]+}}:_(s32) = G_FSIN %{{[0-9]+}}
   %y = call float @llvm.sin.f32(float %x)
   ret float %y
 }
+
+declare float @llvm.sqrt.f32(float)
+define float @test_sqrt_f32(float %x) {
+  ; CHECK-LABEL: name:            test_sqrt_f32
+  ; CHECK: %{{[0-9]+}}:_(s32) = G_FSQRT %{{[0-9]+}}
+  %y = call float @llvm.sqrt.f32(float %x)
+  ret float %y
+}