Add nearbyint support (#774)

* Add support for llvm.nearbyint.* intrinsic

Signed-off-by: Aleksander Fadeev <aleksander.fadeev@intel.com>

Author: fadeeval

llvm-spirv/lib/SPIRV/SPIRVUtil.cpp

@@ -1533,7 +1533,8 @@ bool checkTypeForSPIRVExtendedInstLowering(IntrinsicInst *II, SPIRVModule *BM) {
   switch (II->getIntrinsicID()) {
   case Intrinsic::fabs:
   case Intrinsic::ceil:
-  case Intrinsic::maxnum: {
+  case Intrinsic::maxnum:
+  case Intrinsic::nearbyint: {
     Type *Ty = II->getType();
     if (II->getArgOperand(0)->getType() != Ty)
       return false;

llvm-spirv/lib/SPIRV/SPIRVWriter.cpp

@@ -1986,6 +1986,7 @@ bool LLVMToSPIRV::isKnownIntrinsic(Intrinsic::ID Id) {
   case Intrinsic::fmuladd:
   case Intrinsic::memset:
   case Intrinsic::memcpy:
+  case Intrinsic::nearbyint:
   case Intrinsic::lifetime_start:
   case Intrinsic::lifetime_end:
   case Intrinsic::dbg_declare:
@@ -2316,6 +2317,13 @@ SPIRVValue *LLVMToSPIRV::transIntrinsicInst(IntrinsicInst *II,
       Size = 0;
     return BM->addLifetimeInst(OC, transValue(II->getOperand(1), BB), Size, BB);
   }
+  case Intrinsic::nearbyint: {
+    if (!checkTypeForSPIRVExtendedInstLowering(II, BM))
+      break;
+    return BM->addExtInst(transType(II->getType()),
+                          BM->getExtInstSetId(SPIRVEIS_OpenCL), OpenCLLIB::Rint,
+                          {transValue(II->getOperand(0), BB)}, BB);
+  }
   // We don't want to mix translation of regular code and debug info, because
   // it creates a mess, therefore translation of debug intrinsics is
   // postponed until LLVMToSPIRVDbgTran::finalizeDebug...() methods.

llvm-spirv/test/nearbyint.ll

@@ -0,0 +1,28 @@
+; RUN: llvm-as %s -o %t.bc
+; RUN: llvm-spirv %t.bc -spirv-text -o - | FileCheck %s
+; RUN: llvm-spirv %t.bc -o %t.spv
+; RUN: spirv-val %t.spv
+
+target datalayout = "e-p:32:32-i64:64-v16:16-v24:32-v32:32-v48:64-v96:128-v192:256-v256:256-v512:512-v1024:1024"
+target triple = "spir"
+
+; CHECK: ExtInst {{[0-9]+}} {{[0-9]+}} {{[0-9]+}} rint
+
+; Function Attrs: nounwind readnone
+define dso_local spir_func float @foo(float %x) local_unnamed_addr #0 {
+entry:
+  %0 = tail call float @llvm.nearbyint.f32(float %x)
+  ret float %0
+}
+
+; Function Attrs: nounwind readnone speculatable willreturn
+declare float @llvm.nearbyint.f32(float) #1
+
+attributes #0 = { nounwind readnone "disable-tail-calls"="false" "frame-pointer"="all" "less-precise-fpmad"="false" "min-legal-vector-width"="0" "no-infs-fp-math"="false" "no-jump-tables"="false" "no-nans-fp-math"="false" "no-signed-zeros-fp-math"="false" "no-trapping-math"="true" "stack-protector-buffer-size"="8" "unsafe-fp-math"="false" "use-soft-float"="false" }
+attributes #1 = { nounwind readnone speculatable willreturn }
+
+!llvm.module.flags = !{!0}
+!llvm.ident = !{!1}
+
+!0 = !{i32 1, !"wchar_size", i32 4}
+!1 = !{!"clang version 12.0.0 (https://github.com/llvm/llvm-project.git 68e1a8d20795802077987529e1268c184d749564)"}