[clang] [CIR] Upstream Builtin FloorOp (PR #169954)

[Letu Ren via cfe-commits]

https://github.com/FantasqueX updated https://github.com/llvm/llvm-project/pull/169954

>From f0a25eae56995c6dfd4db5d14b0c18ecabece995 Mon Sep 17 00:00:00 2001
From: Letu Ren <fantasquex at gmail.com>
Date: Sat, 29 Nov 2025 03:27:48 +0800
Subject: [PATCH 1/2] [CIR] Upstream Builtin FloorOp

---
 clang/include/clang/CIR/Dialect/IR/CIROps.td  | 10 +++++++++
 clang/lib/CIR/CodeGen/CIRGenBuiltin.cpp       | 10 +++++++++
 .../CIR/Lowering/DirectToLLVM/LowerToLLVM.cpp |  8 +++++++
 .../CodeGenBuiltins/builtins-floating-point.c | 21 +++++++++++++++++++
 4 files changed, 49 insertions(+)

diff --git a/clang/include/clang/CIR/Dialect/IR/CIROps.td b/clang/include/clang/CIR/Dialect/IR/CIROps.td
index 5f5fab6f12300..dca7fd1485309 100644
--- a/clang/include/clang/CIR/Dialect/IR/CIROps.td
+++ b/clang/include/clang/CIR/Dialect/IR/CIROps.td
@@ -4722,6 +4722,16 @@ def CIR_FAbsOp : CIR_UnaryFPToFPBuiltinOp<"fabs", "FAbsOp"> {
   }];
 }
 
+def CIR_FloorOp : CIR_UnaryFPToFPBuiltinOp<"floor", "FloorOp"> {
+  let summary = "Computes the floating-point floor value";
+  let description = [{
+    `cir.floor` computes the floor of a floating-point operand and returns
+    a result of the same type.
+
+    Floating-point exceptions are ignored, and it does not set `errno`.
+  }];
+}
+
 //===----------------------------------------------------------------------===//
 // Variadic Operations
 //===----------------------------------------------------------------------===//
diff --git a/clang/lib/CIR/CodeGen/CIRGenBuiltin.cpp b/clang/lib/CIR/CodeGen/CIRGenBuiltin.cpp
index 7d4d13121d5e5..8fd3ffeb4e261 100644
--- a/clang/lib/CIR/CodeGen/CIRGenBuiltin.cpp
+++ b/clang/lib/CIR/CodeGen/CIRGenBuiltin.cpp
@@ -321,6 +321,16 @@ RValue CIRGenFunction::emitBuiltinExpr(const GlobalDecl &gd, unsigned builtinID,
   case Builtin::BI__builtin_fabsf128:
     return emitUnaryMaybeConstrainedFPBuiltin<cir::FAbsOp>(*this, *e);
 
+  case Builtin::BIfloor:
+  case Builtin::BIfloorf:
+  case Builtin::BIfloorl:
+  case Builtin::BI__builtin_floor:
+  case Builtin::BI__builtin_floorf:
+  case Builtin::BI__builtin_floorf16:
+  case Builtin::BI__builtin_floorl:
+  case Builtin::BI__builtin_floorf128:
+    return emitUnaryMaybeConstrainedFPBuiltin<cir::FloorOp>(*this, *e);
+
   case Builtin::BI__assume:
   case Builtin::BI__builtin_assume: {
     if (e->getArg(0)->HasSideEffects(getContext()))
diff --git a/clang/lib/CIR/Lowering/DirectToLLVM/LowerToLLVM.cpp b/clang/lib/CIR/Lowering/DirectToLLVM/LowerToLLVM.cpp
index 0c34d87734c3e..25314c3e6cacd 100644
--- a/clang/lib/CIR/Lowering/DirectToLLVM/LowerToLLVM.cpp
+++ b/clang/lib/CIR/Lowering/DirectToLLVM/LowerToLLVM.cpp
@@ -210,6 +210,14 @@ mlir::LogicalResult CIRToLLVMExp2OpLowering::matchAndRewrite(
   return mlir::success();
 }
 
+mlir::LogicalResult CIRToLLVMFloorOpLowering::matchAndRewrite(
+    cir::FloorOp op, OpAdaptor adaptor,
+    mlir::ConversionPatternRewriter &rewriter) const {
+  mlir::Type resTy = typeConverter->convertType(op.getType());
+  rewriter.replaceOpWithNewOp<mlir::LLVM::FFloorOp>(op, resTy, adaptor.getSrc());
+  return mlir::success();
+}
+
 static mlir::Value getLLVMIntCast(mlir::ConversionPatternRewriter &rewriter,
                                   mlir::Value llvmSrc, mlir::Type llvmDstIntTy,
                                   bool isUnsigned, uint64_t cirSrcWidth,
diff --git a/clang/test/CIR/CodeGenBuiltins/builtins-floating-point.c b/clang/test/CIR/CodeGenBuiltins/builtins-floating-point.c
index a4307c57b04b6..010633551f57d 100644
--- a/clang/test/CIR/CodeGenBuiltins/builtins-floating-point.c
+++ b/clang/test/CIR/CodeGenBuiltins/builtins-floating-point.c
@@ -67,3 +67,24 @@ long double my_exp2l(long double f) {
   // LLVM: %{{.*}} = call fp128 @llvm.exp2.f128(fp128 %{{.*}})
   // OGCG: %{{.*}} = call fp128 @llvm.exp2.f128(fp128 %{{.*}})
 }
+
+float floorf(float f) {
+  return __builtin_floorf(f);
+  // CIR: %{{.*}} = cir.floor %{{.*}} : !cir.float
+  // LLVM: %{{.*}} = call float @llvm.floor.f32(float %{{.*}})
+  // OGCG: %{{.*}} = call float @llvm.floor.f32(float %{{.*}})
+}
+
+double floor(double f) {
+  return __builtin_floor(f);
+  // CIR: %{{.*}} = cir.floor %{{.*}} : !cir.double
+  // LLVM: %{{.*}} = call double @llvm.floor.f64(double %{{.*}})
+  // OGCG: %{{.*}} = call double @llvm.floor.f64(double %{{.*}})
+}
+
+long double floorl(long double f) {
+  return __builtin_floorl(f);
+  // CIR: %{{.*}} = cir.floor %{{.*}} : !cir.long_double<!cir.f128>
+  // LLVM: %{{.*}} = call fp128 @llvm.floor.f128(fp128 %{{.*}})
+  // OGCG: %{{.*}} = call fp128 @llvm.floor.f128(fp128 %{{.*}})
+}

>From a9c954efa3763e065c5c2d21adbfe380f481d9d0 Mon Sep 17 00:00:00 2001
From: Letu Ren <fantasquex at gmail.com>
Date: Sat, 29 Nov 2025 03:37:04 +0800
Subject: [PATCH 2/2] fix style

---
 clang/lib/CIR/Lowering/DirectToLLVM/LowerToLLVM.cpp | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/clang/lib/CIR/Lowering/DirectToLLVM/LowerToLLVM.cpp b/clang/lib/CIR/Lowering/DirectToLLVM/LowerToLLVM.cpp
index 25314c3e6cacd..0a0c55123eda2 100644
--- a/clang/lib/CIR/Lowering/DirectToLLVM/LowerToLLVM.cpp
+++ b/clang/lib/CIR/Lowering/DirectToLLVM/LowerToLLVM.cpp
@@ -214,7 +214,8 @@ mlir::LogicalResult CIRToLLVMFloorOpLowering::matchAndRewrite(
     cir::FloorOp op, OpAdaptor adaptor,
     mlir::ConversionPatternRewriter &rewriter) const {
   mlir::Type resTy = typeConverter->convertType(op.getType());
-  rewriter.replaceOpWithNewOp<mlir::LLVM::FFloorOp>(op, resTy, adaptor.getSrc());
+  rewriter.replaceOpWithNewOp<mlir::LLVM::FFloorOp>(op, resTy,
+                                                    adaptor.getSrc());
   return mlir::success();
 }