[mlir][spirv] Add definitions for GL FindILsb and FindSMsb (#143916)

Adds SPIRV GL FindILsb and FindSMsb instructions which correspond to GL
instruction numbers 73 and 74.

Author: fairywreath

mlir/include/mlir/Dialect/SPIRV/IR/SPIRVGLOps.td

@@ -1274,6 +1274,41 @@ def SPIRV_GLReflectOp : SPIRV_GLBinaryArithmeticOp<"Reflect", 71, SPIRV_Float> {
 
 // ----
 
+def SPIRV_GLFindILsbOp : SPIRV_GLUnaryArithmeticOp<"FindILsb", 73, SPIRV_Integer> {
+  let summary = "Integer least-significant bit";
+
+  let description = [{
+    Results in the bit number of the least-significant 1-bit in the binary
+    representation of Value. If Value is 0, the result is -1.
+
+    Result Type and the type of Value must both be integer scalar or
+    integer vector types. Result Type and operand types must have the
+    same number of components with the same component width. Results are
+    computed per component.
+  }];
+}
+
+// ----
+
+def SPIRV_GLFindSMsbOp : SPIRV_GLUnaryArithmeticOp<"FindSMsb", 74, SPIRV_Int32> {
+  let summary = "Signed-integer most-significant bit, with Value interpreted as a signed integer";
+
+  let description = [{
+    For positive numbers, the result will be the bit number of the most significant
+    1-bit. For negative numbers, the result will be the bit number of the most
+    significant 0-bit. For a Value of 0 or -1, the result is -1.
+
+    Result Type and the type of Value must both be integer scalar or
+    integer vector types. Result Type and operand types must have the
+    same number of components with the same component width. Results are
+    computed per component.
+
+    This instruction is currently limited to 32-bit width components.
+  }];
+}
+
+// ----
+
 def SPIRV_GLFindUMsbOp : SPIRV_GLUnaryArithmeticOp<"FindUMsb", 75, SPIRV_Int32> {
   let summary = "Unsigned-integer most-significant bit";
 

mlir/test/Dialect/SPIRV/IR/gl-ops.mlir

@@ -567,7 +567,71 @@ func.func @fmix_vector(%arg0 : vector<3xf32>, %arg1 : vector<3xf32>, %arg2 : vec
 // -----
 
 //===----------------------------------------------------------------------===//
-// spirv.GL.Exp
+// spirv.GL.FindILsb
+//===----------------------------------------------------------------------===//
+
+func.func @findimsb_scalar_i32(%arg0 : i32) -> () {
+  // CHECK: spirv.GL.FindILsb {{%.*}} : i32
+  %2 = spirv.GL.FindILsb %arg0 : i32
+  return
+}
+
+func.func @findimsb_vector_i32(%arg0 : vector<3xi32>) -> () {
+  // CHECK: spirv.GL.FindILsb {{%.*}} : vector<3xi32>
+  %2 = spirv.GL.FindILsb %arg0 : vector<3xi32>
+  return
+}
+
+func.func @findimsb_scalar_i16(%arg0 : i16) -> () {
+  // CHECK: spirv.GL.FindILsb {{%.*}} : i16
+  %2 = spirv.GL.FindILsb %arg0 : i16
+  return
+}
+
+func.func @findimsb_vector_i64(%arg0 : vector<3xi64>) -> () {
+  // CHECK: spirv.GL.FindILsb {{%.*}} : vector<3xi64>
+  %2 = spirv.GL.FindILsb %arg0 : vector<3xi64>
+  return
+}
+
+// -----
+
+func.func @findimsb_error_scalar_float(%arg0 : f32) -> () {
+  // expected-error @+1 {{operand #0 must be 8/16/32/64-bit integer or vector of 8/16/32/64-bit integer values of length 2/3/4/8/1}}
+  %2 = spirv.GL.FindILsb %arg0 : f32
+  return
+}
+
+// -----
+
+//===----------------------------------------------------------------------===//
+// spirv.GL.FindSMsb
+//===----------------------------------------------------------------------===//
+
+func.func @findsmsb_scalar(%arg0 : i32) -> () {
+  // CHECK: spirv.GL.FindSMsb {{%.*}} : i32
+  %2 = spirv.GL.FindSMsb %arg0 : i32
+  return
+}
+
+func.func @findsmsb_vector(%arg0 : vector<3xi32>) -> () {
+  // CHECK: spirv.GL.FindSMsb {{%.*}} : vector<3xi32>
+  %2 = spirv.GL.FindSMsb %arg0 : vector<3xi32>
+  return
+}
+
+// -----
+
+func.func @findsmsb_error_scalar_i64(%arg0 : i64) -> () {
+  // expected-error @+1 {{operand #0 must be Int32 or vector of Int32}}
+  %2 = spirv.GL.FindSMsb %arg0 : i64
+  return
+}
+
+// -----
+
+//===----------------------------------------------------------------------===//
+// spirv.GL.FindUMsb
 //===----------------------------------------------------------------------===//
 
 func.func @findumsb(%arg0 : i32) -> () {

mlir/test/Target/SPIRV/gl-ops.mlir

@@ -90,13 +90,24 @@ spirv.module Logical GLSL450 requires #spirv.vce<v1.0, [Shader], []> {
     spirv.Return
   }
 
+  spirv.func @findilsb(%arg0 : i32) "None" {
+    // CHECK: spirv.GL.FindILsb {{%.*}} : i32
+    %2 = spirv.GL.FindILsb %arg0 : i32
+    spirv.Return
+  }
+  spirv.func @findsmsb(%arg0 : i32) "None" {
+    // CHECK: spirv.GL.FindSMsb {{%.*}} : i32
+    %2 = spirv.GL.FindSMsb %arg0 : i32
+    spirv.Return
+  }
+
   spirv.func @findumsb(%arg0 : i32) "None" {
     // CHECK: spirv.GL.FindUMsb {{%.*}} : i32
     %2 = spirv.GL.FindUMsb %arg0 : i32
     spirv.Return
   }
 
-  spirv.func @vector(%arg0 : f32, %arg1 : vector<3xf32>, %arg2 : vector<3xf32>) "None" {
+  spirv.func @vector(%arg0 : f32, %arg1 : vector<3xf32>, %arg2 : vector<3xf32>, %arg3: vector<3xi32>) "None" {
     // CHECK: {{%.*}} = spirv.GL.Cross {{%.*}}, {{%.*}} : vector<3xf32>
     %0 = spirv.GL.Cross %arg1, %arg2 : vector<3xf32>
     // CHECK: {{%.*}} = spirv.GL.Normalize {{%.*}} : f32
@@ -111,6 +122,12 @@ spirv.module Logical GLSL450 requires #spirv.vce<v1.0, [Shader], []> {
     %5 = spirv.GL.Distance %arg0, %arg0 : f32, f32 -> f32
     // CHECK: {{%.*}} = spirv.GL.Distance {{%.*}}, {{%.*}} : vector<3xf32>, vector<3xf32> -> f32
     %6 = spirv.GL.Distance %arg1, %arg2 : vector<3xf32>, vector<3xf32> -> f32
+    // CHECK: {{%.*}} = spirv.GL.FindILsb {{%.*}} : vector<3xi32>
+    %7 = spirv.GL.FindILsb %arg3 : vector<3xi32>
+    // CHECK: {{%.*}} = spirv.GL.FindSMsb {{%.*}} : vector<3xi32>
+    %8 = spirv.GL.FindSMsb %arg3 : vector<3xi32>
+    // CHECK: {{%.*}} = spirv.GL.FindUMsb {{%.*}} : vector<3xi32>
+    %9 = spirv.GL.FindUMsb %arg3 : vector<3xi32>
     spirv.Return
   }