[Mlir-commits] [mlir] [MLIR][NVVM] Add `nvvm.ex2` OP (PR #193790)

[Guray Ozen]

https://github.com/grypp updated https://github.com/llvm/llvm-project/pull/193790

>From 2c85fe12765044ef899cb793e7b5b39ddde6bd00 Mon Sep 17 00:00:00 2001
From: Guray Ozen <gozen at nvidia.com>
Date: Fri, 24 Apr 2026 12:43:02 +0200
Subject: [PATCH] [MLIR][NVVM] Add `nvvm.ex2` OP

Implement `nvvm.ex2` with ftz flag

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply at anthropic.com>
---
 mlir/include/mlir/Dialect/LLVMIR/NVVMOps.td        | 14 ++++++++++++++
 mlir/lib/Dialect/LLVMIR/IR/NVVMDialect.cpp         | 10 ++++++++++
 mlir/test/Dialect/LLVMIR/nvvm-transcendentals.mlir | 14 ++++++++++++++
 mlir/test/Target/LLVMIR/nvvm/transcendentals.mlir  | 14 ++++++++++++++
 4 files changed, 52 insertions(+)

diff --git a/mlir/include/mlir/Dialect/LLVMIR/NVVMOps.td b/mlir/include/mlir/Dialect/LLVMIR/NVVMOps.td
index 9e94477c3a60a..dafbd8085de60 100644
--- a/mlir/include/mlir/Dialect/LLVMIR/NVVMOps.td
+++ b/mlir/include/mlir/Dialect/LLVMIR/NVVMOps.td
@@ -543,6 +543,20 @@ def NVVM_SinOp : NVVM_SingleResultIntrinsicOp<"sin",
   let assemblyFormat = "$src attr-dict `:` type($src)";
 }
 
+def NVVM_Ex2Op : NVVM_SingleResultIntrinsicOp<"ex2",
+    [Pure, SameOperandsAndResultType]> {
+  let summary = "Base-2 exponential (fast approximation)";
+  let description = [{
+    Computes a fast approximation of 2 raised to the power of the input
+    value. The `ftz` attribute, when set, flushes subnormal inputs and
+    results to sign-preserving zero.
+  }];
+  let arguments = (ins F32:$src,
+                       DefaultValuedAttr<BoolAttr, "false">:$ftz);
+  let results = (outs F32:$res);
+  let assemblyFormat = "$src attr-dict `:` type($src)";
+}
+
 //===----------------------------------------------------------------------===//
 // NVVM redux op definitions
 //===----------------------------------------------------------------------===//
diff --git a/mlir/lib/Dialect/LLVMIR/IR/NVVMDialect.cpp b/mlir/lib/Dialect/LLVMIR/IR/NVVMDialect.cpp
index b0cebd45624a9..c8eac290bbf20 100644
--- a/mlir/lib/Dialect/LLVMIR/IR/NVVMDialect.cpp
+++ b/mlir/lib/Dialect/LLVMIR/IR/NVVMDialect.cpp
@@ -3474,6 +3474,16 @@ SinOp::getIntrinsicIDAndArgs(Operation &op, LLVM::ModuleTranslation &mt,
   return {id, {mt.lookupValue(thisOp.getSrc())}};
 }
 
+mlir::NVVM::IDArgPair
+Ex2Op::getIntrinsicIDAndArgs(Operation &op, LLVM::ModuleTranslation &mt,
+                             llvm::IRBuilderBase &builder) {
+  auto thisOp = cast<NVVM::Ex2Op>(op);
+  llvm::Intrinsic::ID id = thisOp.getFtz()
+                               ? llvm::Intrinsic::nvvm_ex2_approx_ftz
+                               : llvm::Intrinsic::nvvm_ex2_approx;
+  return {id, {mt.lookupValue(thisOp.getSrc())}};
+}
+
 mlir::NVVM::IDArgPair
 PMEventOp::getIntrinsicIDAndArgs(Operation &op, LLVM::ModuleTranslation &mt,
                                  llvm::IRBuilderBase &builder) {
diff --git a/mlir/test/Dialect/LLVMIR/nvvm-transcendentals.mlir b/mlir/test/Dialect/LLVMIR/nvvm-transcendentals.mlir
index c773e3f06a612..5391db1c93640 100644
--- a/mlir/test/Dialect/LLVMIR/nvvm-transcendentals.mlir
+++ b/mlir/test/Dialect/LLVMIR/nvvm-transcendentals.mlir
@@ -13,3 +13,17 @@ func.func @nvvm_sin_ftz_f32(%arg0: f32) -> f32 {
   %0 = nvvm.sin %arg0 {ftz = true} : f32
   return %0 : f32
 }
+
+// CHECK-LABEL: @nvvm_ex2_f32
+func.func @nvvm_ex2_f32(%arg0: f32) -> f32 {
+  // CHECK: nvvm.ex2 {{.*}} : f32
+  %0 = nvvm.ex2 %arg0 : f32
+  return %0 : f32
+}
+
+// CHECK-LABEL: @nvvm_ex2_ftz_f32
+func.func @nvvm_ex2_ftz_f32(%arg0: f32) -> f32 {
+  // CHECK: nvvm.ex2 {{.*}} {ftz = true} : f32
+  %0 = nvvm.ex2 %arg0 {ftz = true} : f32
+  return %0 : f32
+}
diff --git a/mlir/test/Target/LLVMIR/nvvm/transcendentals.mlir b/mlir/test/Target/LLVMIR/nvvm/transcendentals.mlir
index 65374c9bd5e87..4830bf79eacd0 100644
--- a/mlir/test/Target/LLVMIR/nvvm/transcendentals.mlir
+++ b/mlir/test/Target/LLVMIR/nvvm/transcendentals.mlir
@@ -13,3 +13,17 @@ llvm.func @nvvm_sin_ftz(%arg0: f32) -> f32 {
   %0 = nvvm.sin %arg0 {ftz = true} : f32
   llvm.return %0 : f32
 }
+
+// CHECK-LABEL: @nvvm_ex2
+llvm.func @nvvm_ex2(%arg0: f32) -> f32 {
+  // CHECK: call float @llvm.nvvm.ex2.approx.f32(float %{{.*}})
+  %0 = nvvm.ex2 %arg0 : f32
+  llvm.return %0 : f32
+}
+
+// CHECK-LABEL: @nvvm_ex2_ftz
+llvm.func @nvvm_ex2_ftz(%arg0: f32) -> f32 {
+  // CHECK: call float @llvm.nvvm.ex2.approx.ftz.f32(float %{{.*}})
+  %0 = nvvm.ex2 %arg0 {ftz = true} : f32
+  llvm.return %0 : f32
+}