[Mlir-commits] [mlir] [mlir][[spirv] Add support for math.log2 and math.log10 to GLSL/OpenCL SPIRV Backends (PR #104608)

[Jakub Kuderski]

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@@ -291,6 +291,65 @@ struct Log1pOpPattern final : public OpConversionPattern<math::Log1pOp> {
   }
 };
 
+/// Converts math.log2 and math.log10 to SPIR-V ops.
+///
+/// SPIR-V does not have direct operations for log2 and log10. Explicitly
+/// lower to these operations using:
+///   log2(x) = log(x) * 1/log(2)
+///   log10(x) = log(x) * 1/log(10)
+
+#define LOG2_RECIPROCAL                                                        \
+  1.442695040888963407359924681001892137426645954152985934135449407
+#define LOG10_RECIPROCAL                                                       \
+  0.4342944819032518276511289189166050822943970058036665661144537832
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kuhar wrote:

You can define these at the class level with `static constexpr double xyz = 1.442...;`

https://github.com/llvm/llvm-project/pull/104608