[Mlir-commits] [mlir] [mlir][spirv] Add definition for GL Log2 (PR #143409)

[Igor Wodiany]

https://github.com/IgWod-IMG updated https://github.com/llvm/llvm-project/pull/143409

>From f90d488f23845078228a83cbb2cfad32bed2edca Mon Sep 17 00:00:00 2001
From: Igor Wodiany <igor.wodiany at imgtec.com>
Date: Mon, 9 Jun 2025 16:53:28 +0100
Subject: [PATCH 1/2] [mlir][spirv] Add definition for GL Log2

---
 .../mlir/Dialect/SPIRV/IR/SPIRVGLOps.td       | 30 +++++++++++++++++++
 mlir/test/Dialect/SPIRV/IR/gl-ops.mlir        | 26 ++++++++++++++++
 mlir/test/Target/SPIRV/gl-ops.mlir            |  2 ++
 3 files changed, 58 insertions(+)

diff --git a/mlir/include/mlir/Dialect/SPIRV/IR/SPIRVGLOps.td b/mlir/include/mlir/Dialect/SPIRV/IR/SPIRVGLOps.td
index 057dfac4d6308..8c5a0b858c42d 100644
--- a/mlir/include/mlir/Dialect/SPIRV/IR/SPIRVGLOps.td
+++ b/mlir/include/mlir/Dialect/SPIRV/IR/SPIRVGLOps.td
@@ -767,6 +767,36 @@ def SPIRV_GLTanhOp : SPIRV_GLUnaryArithmeticOp<"Tanh", 21, SPIRV_Float16or32> {
 
 // -----
 
+def SPIRV_GLLog2Op : SPIRV_GLUnaryArithmeticOp<"Log2", 30, SPIRV_Float16or32> {
+  let summary = "Result is the base-2 logarithm of x";
+
+  let description = [{
+    Result is the base-2 logarithm of x, i.e., the value y which satisfies the
+    equation x = 2y. The resulting value is NaN if x < 0. Moreover:
+
+    ```
+    log(Inf) = Inf
+    log(1.0) = +0
+    log(±0) = -Inf
+    ```
+
+    The operand x must be a scalar or vector whose component type is 16-bit or
+    32-bit floating-point.
+
+    Result Type and the type of x must be the same type. Results are computed
+    per component.
+
+    #### Example:
+
+    ```mlir
+    %2 = spirv.GL.Log2 %0 : f32
+    %3 = spirv.GL.Log2 %1 : vector<3xf16>
+    ```
+  }];
+}
+
+// -----
+
 def SPIRV_GLFClampOp : SPIRV_GLTernaryArithmeticOp<"FClamp", 43, SPIRV_Float> {
   let summary = "Clamp x between min and max values.";
 
diff --git a/mlir/test/Dialect/SPIRV/IR/gl-ops.mlir b/mlir/test/Dialect/SPIRV/IR/gl-ops.mlir
index 0be047932c1f3..8f8e9e3a2417d 100644
--- a/mlir/test/Dialect/SPIRV/IR/gl-ops.mlir
+++ b/mlir/test/Dialect/SPIRV/IR/gl-ops.mlir
@@ -689,3 +689,29 @@ func.func @fract_invalid_type(%arg0 : i32) {
   %0 = spirv.GL.Fract %arg0 : i32
   return
 }
+
+// -----
+
+//===----------------------------------------------------------------------===//
+// spirv.GL.Log2
+//===----------------------------------------------------------------------===//
+
+func.func @log2(%arg0 : f32) -> () {
+  // CHECK: spirv.GL.Log2 {{%.*}} : f32
+  %0 = spirv.GL.Log2 %arg0 : f32
+  return
+}
+
+func.func @log2vec(%arg0 : vector<3xf16>) -> () {
+  // CHECK: spirv.GL.Log2 {{%.*}} : vector<3xf16>
+  %0 = spirv.GL.Log2 %arg0 : vector<3xf16>
+  return
+}
+
+// -----
+
+func.func @log2_invalid_type(%arg0 : i32) -> () {
+  // expected-error @+1 {{op operand #0 must be 16/32-bit float or vector of 16/32-bit float values}}
+  %0 = spirv.GL.Log2 %arg0 : i32
+  return
+}
diff --git a/mlir/test/Target/SPIRV/gl-ops.mlir b/mlir/test/Target/SPIRV/gl-ops.mlir
index 7f9771220b75d..bd6cf5957fac6 100644
--- a/mlir/test/Target/SPIRV/gl-ops.mlir
+++ b/mlir/test/Target/SPIRV/gl-ops.mlir
@@ -34,6 +34,8 @@ spirv.module Logical GLSL450 requires #spirv.vce<v1.0, [Shader], []> {
     %15 = spirv.GL.FMix %arg0 : f32, %arg1 : f32, %arg0 : f32 -> f32
     // CHECK: {{%.*}} = spirv.GL.Fract {{%.*}} : f32
     %16 = spirv.GL.Fract %arg0 : f32
+    // CHECK: {{%.*}} = spirv.GL.Log2 {{%.*}} : f32
+    %17 = spirv.GL.Log2 %arg0 : f32
     spirv.Return
   }
 

>From f54745d91af0813c52df57f0438eb31b4646ee95 Mon Sep 17 00:00:00 2001
From: Igor Wodiany <igor.wodiany at imgtec.com>
Date: Mon, 9 Jun 2025 18:18:20 +0100
Subject: [PATCH 2/2] Fix typo

Co-authored-by: Jakub Kuderski <kubakuderski at gmail.com>
---
 mlir/include/mlir/Dialect/SPIRV/IR/SPIRVGLOps.td | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/mlir/include/mlir/Dialect/SPIRV/IR/SPIRVGLOps.td b/mlir/include/mlir/Dialect/SPIRV/IR/SPIRVGLOps.td
index 8c5a0b858c42d..047c6ad434e98 100644
--- a/mlir/include/mlir/Dialect/SPIRV/IR/SPIRVGLOps.td
+++ b/mlir/include/mlir/Dialect/SPIRV/IR/SPIRVGLOps.td
@@ -772,7 +772,7 @@ def SPIRV_GLLog2Op : SPIRV_GLUnaryArithmeticOp<"Log2", 30, SPIRV_Float16or32> {
 
   let description = [{
     Result is the base-2 logarithm of x, i.e., the value y which satisfies the
-    equation x = 2y. The resulting value is NaN if x < 0. Moreover:
+    equation x = 2**y. The resulting value is NaN if x < 0. Moreover:
 
     ```
     log(Inf) = Inf