[Mlir-commits] [mlir] [mlir][emitc] Support convert arith.extf and arith.truncf to emitc (PR #121184)

[Marius Brehler]

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@@ -733,6 +733,43 @@ class ItoFCastOpConversion : public OpConversionPattern<CastOp> {
   }
 };
 
+// Floating-point to floating-point conversions.
+template <typename CastOp>
+class FpCastOpConversion : public OpConversionPattern<CastOp> {
+public:
+  FpCastOpConversion(const TypeConverter &typeConverter, MLIRContext *context)
+      : OpConversionPattern<CastOp>(typeConverter, context) {}
+
+  LogicalResult
+  matchAndRewrite(CastOp castOp, typename CastOp::Adaptor adaptor,
+                  ConversionPatternRewriter &rewriter) const override {
+    // Vectors in particular are not supported
+    Type operandType = adaptor.getIn().getType();
+    if (!emitc::isSupportedFloatType(operandType))
+      return rewriter.notifyMatchFailure(castOp,
+                                         "unsupported cast source type");
+    if (auto roundingModeOp =
+            dyn_cast<arith::ArithRoundingModeInterface>(*castOp)) {
+      // Only supporting default rounding mode as of now.
+      if (roundingModeOp.getRoundingModeAttr())
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marbre wrote:

Fair enough. The one difference however might be that the SPRI-V as well as the amdgpu dialect specify what rounding modes they assume in general. Maybe we could add at least some documentation to e.g. `emitc.td`? 

https://github.com/llvm/llvm-project/pull/121184