The powers that be have decided that LLVM IR should now support 16-bit

"half precision" floating-point with a first-class type.

This patch adds basic IR support (but not codegen support).


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@146786 91177308-0d34-0410-b5e6-96231b3b80d8

2 files changed, 6 insertions, 1 deletions

diff --git a/lib/Transforms/InstCombine/InstCombineCasts.cpp b/lib/Transforms/InstCombine/InstCombineCasts.cpp
index 46e4acde7b..49a498ff5f 100644
--- a/lib/Transforms/InstCombine/InstCombineCasts.cpp
+++ b/lib/Transforms/InstCombine/InstCombineCasts.cpp
@@ -1160,6 +1160,9 @@ static Value *LookThroughFPExtensions(Value *V) {
   if (ConstantFP *CFP = dyn_cast<ConstantFP>(V)) {
     if (CFP->getType() == Type::getPPC_FP128Ty(V->getContext()))
       return V;  // No constant folding of this.
+    // See if the value can be truncated to half and then reextended.
+    if (Value *V = FitsInFPType(CFP, APFloat::IEEEhalf))
+      return V;
     // See if the value can be truncated to float and then reextended.
     if (Value *V = FitsInFPType(CFP, APFloat::IEEEsingle))
       return V;
diff --git a/lib/Transforms/InstCombine/InstCombineCompares.cpp b/lib/Transforms/InstCombine/InstCombineCompares.cpp
index 144b92b362..4427f4be58 100644
--- a/lib/Transforms/InstCombine/InstCombineCompares.cpp
+++ b/lib/Transforms/InstCombine/InstCombineCompares.cpp
@@ -2848,7 +2848,9 @@ Instruction *InstCombiner::visitFCmpInst(FCmpInst &I) {
 
         const fltSemantics *Sem;
         // FIXME: This shouldn't be here.
-        if (LHSExt->getSrcTy()->isFloatTy())
+        if (LHSExt->getSrcTy()->isHalfTy())
+          Sem = &APFloat::IEEEhalf;
+        else if (LHSExt->getSrcTy()->isFloatTy())
           Sem = &APFloat::IEEEsingle;
         else if (LHSExt->getSrcTy()->isDoubleTy())
           Sem = &APFloat::IEEEdouble;