[llvm] c0c4c72 - [RISCV] Return false for unsupported VTs in isFPImmLegal.

[Craig Topper via llvm-commits]

Author: Craig Topper
Date: 2023-03-12T23:34:13-07:00
New Revision: c0c4c725e98c7339d8dbc8eec2a773d26f87929b

URL: https://github.com/llvm/llvm-project/commit/c0c4c725e98c7339d8dbc8eec2a773d26f87929b
DIFF: https://github.com/llvm/llvm-project/commit/c0c4c725e98c7339d8dbc8eec2a773d26f87929b.diff

LOG: [RISCV] Return false for unsupported VTs in isFPImmLegal.

I don't have a test case that fails for this, but it seemed like
we should only handle legal types. The callers I looked at in
DAGCombine either check the type is legal or don't even call
isFPImmLegal unless LegalOperations is true.

Written in a slightly odd way because switches on EVT require
an additional isSimple check so an if/else chain is easier. Used a bool
to shorten the code instead of having multiple ifs and returns.
AArch64 uses a similarish structure.

Added: 
    

Modified: 
    llvm/lib/Target/RISCV/RISCVISelLowering.cpp

Removed: 
    


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diff  --git a/llvm/lib/Target/RISCV/RISCVISelLowering.cpp b/llvm/lib/Target/RISCV/RISCVISelLowering.cpp
index 95009ca9cd14..c8a9d02d7062 100644
--- a/llvm/lib/Target/RISCV/RISCVISelLowering.cpp
+++ b/llvm/lib/Target/RISCV/RISCVISelLowering.cpp
@@ -1558,11 +1558,15 @@ bool RISCVTargetLowering::isLegalZfaFPImm(const APFloat &Imm, EVT VT) const {
 
 bool RISCVTargetLowering::isFPImmLegal(const APFloat &Imm, EVT VT,
                                        bool ForCodeSize) const {
-  if (VT == MVT::f16 && !Subtarget.hasStdExtZfhOrZfhmin())
-    return false;
-  if (VT == MVT::f32 && !Subtarget.hasStdExtF())
-    return false;
-  if (VT == MVT::f64 && !Subtarget.hasStdExtD())
+  bool IsLegalVT = false;
+  if (VT == MVT::f16)
+    IsLegalVT = Subtarget.hasStdExtZfhOrZfhmin();
+  else if (VT == MVT::f32)
+    IsLegalVT = Subtarget.hasStdExtF();
+  else if (VT == MVT::f64)
+    IsLegalVT = Subtarget.hasStdExtD();
+
+  if (!IsLegalVT)
     return false;
 
   if (isLegalZfaFPImm(Imm, VT))