[CIR] Enable floating point casts

[andykaylor]

We already had the code in place to emit CIR floating point cast ops that get lowered to fpext or fptrunc, but we weren't calling the function to emit that cast from ScalarExprEmitter::emitScalarCast. This change adds that call.

[llvmbot]

@llvm/pr-subscribers-clangir

@llvm/pr-subscribers-clang

Author: Andy Kaylor (andykaylor)

Changes

We already had the code in place to emit CIR floating point cast ops that get lowered to fpext or fptrunc, but we weren't calling the function to emit that cast from ScalarExprEmitter::emitScalarCast. This change adds that call.

---

Full diff: https://github.com/llvm/llvm-project/pull/144142.diff

2 Files Affected:

• (modified) clang/lib/CIR/CodeGen/CIRGenExprScalar.cpp (+2-2)
• (modified) clang/test/CIR/CodeGen/cast.cpp (+8)

diff --git a/clang/lib/CIR/CodeGen/CIRGenExprScalar.cpp b/clang/lib/CIR/CodeGen/CIRGenExprScalar.cpp
index 30d231e2c61de..baaef022ccc68 100644
--- a/clang/lib/CIR/CodeGen/CIRGenExprScalar.cpp
+++ b/clang/lib/CIR/CodeGen/CIRGenExprScalar.cpp
@@ -346,8 +346,8 @@ class ScalarExprEmitter : public StmtVisitor<ScalarExprEmitter, mlir::Value> {
         assert(!cir::MissingFeatures::fpConstraints());
         castKind = cir::CastKind::float_to_int;
       } else if (mlir::isa<cir::CIRFPTypeInterface>(dstTy)) {
-        cgf.getCIRGenModule().errorNYI("floating point casts");
-        return cgf.createDummyValue(src.getLoc(), dstType);
+        // TODO: split this to createFPExt/createFPTrunc
+        return builder.createFloatingCast(src, fullDstTy);
       } else {
         llvm_unreachable("Internal error: Cast to unexpected type");
       }
diff --git a/clang/test/CIR/CodeGen/cast.cpp b/clang/test/CIR/CodeGen/cast.cpp
index a7c11b1939ba5..84f55242a6118 100644
--- a/clang/test/CIR/CodeGen/cast.cpp
+++ b/clang/test/CIR/CodeGen/cast.cpp
@@ -73,6 +73,14 @@ int cStyleCasts_0(unsigned x1, int x2, float x3, short x4, double x5) {
   // LLVM: %{{[0-9]+}} = fcmp une float %{{[0-9]+}}, 0.000000e+00
   // LLVM: %{{[0-9]+}} = zext i1 %{{[0-9]+}} to i8
 
+  double d2 = f; // float to double
+  // CIR: %{{[0-9]+}} = cir.cast(floating, %{{[0-9]+}} : !cir.float), !cir.double
+  // LLVM: %{{[0-9]+}} = fpext float %{{[0-9]+}} to double
+
+  f = d2; // double to float
+  // CIR: %{{[0-9]+}} = cir.cast(floating, %{{[0-9]+}} : !cir.double), !cir.float
+  // LLVM: %{{[0-9]+}} = fptrunc double %{{[0-9]+}} to float
+
   return 0;
 }
 

[AmrDeveloper]

LGTM