[CIR] Upstream FPToFPBuiltin ATanOp

clang/include/clang/CIR/Dialect/IR/CIROps.td

@@ -3837,6 +3837,16 @@ def CIR_ASinOp : CIR_UnaryFPToFPBuiltinOp<"asin", "ASinOp"> {
   }];
 }
 
+def CIR_ATanOp : CIR_UnaryFPToFPBuiltinOp<"atan", "ATanOp"> {
+  let summary = "Computes the floating-point arcus tangent value";
+  let description = [{
+    `cir.atan` computes the arcus tangent of a floating-point operand
+    and returns a result of the same type.
+
+    Floating-point exceptions are ignored, and it does not set `errno`.
+  }];
+}
+
 def CIR_FAbsOp : CIR_UnaryFPToFPBuiltinOp<"fabs", "FAbsOp"> {
   let summary = "Computes the floating-point absolute value";
   let description = [{

clang/lib/CIR/CodeGen/CIRGenBuiltin.cpp

@@ -413,6 +413,8 @@ RValue CIRGenFunction::emitBuiltinExpr(const GlobalDecl &gd, unsigned builtinID,
     return emitUnaryFPBuiltin<cir::ACosOp>(*this, *e);
   case Builtin::BI__builtin_elementwise_asin:
     return emitUnaryFPBuiltin<cir::ASinOp>(*this, *e);
+  case Builtin::BI__builtin_elementwise_atan:
+    return emitUnaryFPBuiltin<cir::ATanOp>(*this, *e);
   }
 
   // If this is an alias for a lib function (e.g. __builtin_sin), emit

clang/lib/CIR/Lowering/DirectToLLVM/LowerToLLVM.cpp

@@ -1103,6 +1103,14 @@ mlir::LogicalResult CIRToLLVMBaseClassAddrOpLowering::matchAndRewrite(
   return mlir::success();
 }
 
+mlir::LogicalResult CIRToLLVMATanOpLowering::matchAndRewrite(
+    cir::ATanOp op, OpAdaptor adaptor,
+    mlir::ConversionPatternRewriter &rewriter) const {
+  mlir::Type resTy = typeConverter->convertType(op.getType());
+  rewriter.replaceOpWithNewOp<mlir::LLVM::ATanOp>(op, resTy, adaptor.getSrc());
+  return mlir::success();
+}
+
 mlir::LogicalResult CIRToLLVMAllocaOpLowering::matchAndRewrite(
     cir::AllocaOp op, OpAdaptor adaptor,
     mlir::ConversionPatternRewriter &rewriter) const {
@@ -2468,6 +2476,7 @@ void ConvertCIRToLLVMPass::runOnOperation() {
                CIRToLLVMAssumeSepStorageOpLowering,
                CIRToLLVMAtomicCmpXchgLowering,
                CIRToLLVMBaseClassAddrOpLowering,
+               CIRToLLVMATanOpLowering,
                CIRToLLVMBinOpLowering,
                CIRToLLVMBitClrsbOpLowering,
                CIRToLLVMBitClzOpLowering,

clang/lib/CIR/Lowering/DirectToLLVM/LowerToLLVM.h

@@ -755,6 +755,15 @@ class CIRToLLVMASinOpLowering : public mlir::OpConversionPattern<cir::ASinOp> {
                   mlir::ConversionPatternRewriter &) const override;
 };
 
+class CIRToLLVMATanOpLowering : public mlir::OpConversionPattern<cir::ATanOp> {
+public:
+  using mlir::OpConversionPattern<cir::ATanOp>::OpConversionPattern;
+
+  mlir::LogicalResult
+  matchAndRewrite(cir::ATanOp op, OpAdaptor,
+                  mlir::ConversionPatternRewriter &) const override;
+};
+
 class CIRToLLVMInlineAsmOpLowering
     : public mlir::OpConversionPattern<cir::InlineAsmOp> {
   mlir::DataLayout const &dataLayout;

clang/test/CIR/CodeGen/builtins-elementwise.c

@@ -62,3 +62,30 @@ void test_builtin_elementwise_asin(float f, double d, vfloat4 vf4,
   // OGCG: %{{.*}} = call <4 x double> @llvm.asin.v4f64(<4 x double> %{{.*}})
   vd4 = __builtin_elementwise_asin(vd4);
 }
+
+void test_builtin_elementwise_atan(float f, double d, vfloat4 vf4,
+  vdouble4  vd4) {
+  // CIR-LABEL: test_builtin_elementwise_atan
+  // LLVM-LABEL: test_builtin_elementwise_atan
+  // OGCG-LABEL: test_builtin_elementwise_atan
+
+  // CIR: %{{.*}} = cir.atan %{{.*}} : !cir.float
+  // LLVM: %{{.*}} = call float @llvm.atan.f32(float %{{.*}})
+  // OGCG: %{{.*}} = call float @llvm.atan.f32(float %{{.*}})
+  f = __builtin_elementwise_atan(f);
+
+  // CIR: %{{.*}} = cir.atan %{{.*}} : !cir.double
+  // LLVM: %{{.*}} = call double @llvm.atan.f64(double %{{.*}})
+  // OGCG: %{{.*}} = call double @llvm.atan.f64(double %{{.*}})
+  d = __builtin_elementwise_atan(d);
+
+  // CIR: %{{.*}} = cir.atan %{{.*}} : !cir.vector<4 x !cir.float>
+  // LLVM: %{{.*}} = call <4 x float> @llvm.atan.v4f32(<4 x float> %{{.*}})
+  // OGCG: %{{.*}} = call <4 x float> @llvm.atan.v4f32(<4 x float> %{{.*}})
+  vf4 = __builtin_elementwise_atan(vf4);
+
+  // CIR: %{{.*}} = cir.atan %{{.*}} : !cir.vector<4 x !cir.double>
+  // LLVM: %{{.*}} = call <4 x double> @llvm.atan.v4f64(<4 x double> %{{.*}})
+  // OGCG: %{{.*}} = call <4 x double> @llvm.atan.v4f64(<4 x double> %{{.*}})
+  vd4 = __builtin_elementwise_atan(vd4);
+}