[Mlir-commits] [mlir] 9c224fd - [MLIR][SPIRVToLLVM] Updated the documentation for type conversion

[George Mitenkov]

Author: George Mitenkov
Date: 2020-08-27T07:47:55+03:00
New Revision: 9c224fd48ae56ab86f543c53eea6d8a5427dd37c

URL: https://github.com/llvm/llvm-project/commit/9c224fd48ae56ab86f543c53eea6d8a5427dd37c
DIFF: https://github.com/llvm/llvm-project/commit/9c224fd48ae56ab86f543c53eea6d8a5427dd37c.diff

LOG: [MLIR][SPIRVToLLVM] Updated the documentation for type conversion

This patch updates the type conversion section of the documentation.
It includes the modelling of array strides and the mapping of the
naturally padded structs.

Reviewed By: mravishankar

Differential Revision: https://reviews.llvm.org/D86674

Added: 
    

Modified: 
    mlir/docs/SPIRVToLLVMDialectConversion.md

Removed: 
    


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diff  --git a/mlir/docs/SPIRVToLLVMDialectConversion.md b/mlir/docs/SPIRVToLLVMDialectConversion.md
index c5a157930527..c28128e0e7eb 100644
--- a/mlir/docs/SPIRVToLLVMDialectConversion.md
+++ b/mlir/docs/SPIRVToLLVMDialectConversion.md
@@ -54,8 +54,9 @@ which is not known at compile time. In LLVM, it is possible to index beyond the
 end of the array. Therfore, runtime array can be implemented as a zero length
 array type.
 
-Moreover, SPIR-V supports the notion of array stride. Note that this is **not**
-supported by type conversion at the moment.
+Moreover, SPIR-V supports the notion of array stride. Currently only natural
+strides (based on [`VulkanLayoutUtils`](VulkanLayoutUtils)) are supported. They
+are also mapped to LLVM array.
 
 SPIR-V Dialect                        | LLVM Dialect
 :-----------------------------------: | :-----------------------------------:
@@ -77,8 +78,7 @@ at the moment. Hence, we adhere to the following mapping:
 
 *   Structs with natural offset (*i.e.* offset that equals to cumulative size of
     the previous struct elements or is a natural alignment) are mapped to
-    naturally padded structs. Nested structs with offset and structs with offset
-    containing arrays are **not** supported.
+    naturally padded structs.
 
 *   Structs with unnatural offset (*i.e.* offset that is not equal to cumulative
     size of the previous struct elements) are **not** supported. In this case,
@@ -783,3 +783,4 @@ to LLVM ops. At the moment, SPIR-V module attributes are ignored.
 
 [LLVMFunctionAttributes]: https://llvm.org/docs/LangRef.html#function-attributes
 [SPIRVFunctionAttributes]: https://www.khronos.org/registry/spir-v/specs/unified1/SPIRV.html#_a_id_function_control_a_function_control
+[VulkanLayoutUtils]: https://github.com/llvm/llvm-project/blob/master/mlir/include/mlir/Dialect/SPIRV/LayoutUtils.h