[MLIR] Add printf op from SPIRV OpenCL extension set spec

[drprajap]

Summary

This change adds op to support printf instruction from OpenCL extensions set.

This op helps writing out debug details from SPIRV kernel in a given format.

[drprajap]

Fixed printf test

[kuhar]

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

79

IIRC Pure implies (1) no memory effects and (2) speculability. Are we sure that this is this the case with printf? Alternatively, would it make sense to remove this trait from the base class for all misc ops or to remove this class all together since it has a single use right now?

782–789

This summary is a bit long - would it make sense to punt some conte to description instead? We edited some auto-generated summaries already, so I don't think this would create a new precedent.

[antiagainst]

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

79

Ah, good catch. Thanks for spotting this! :)

[drprajap]

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

79

aah, my mistake! thanks for catching it. For adding separate base class, thought that was convention where other ops are grouped in some base class and actual op extends that. But seeing the printf Op usage, I can remove base.

782–789

Sure. I can move some to description.

[drprajap]

Removed MiscOp base class and corrected traits

[kuhar]

LGTM, thanks for the fixes! Just a few nits.

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

788

nit: unnecessary empty line?

792

nit: missing . at the end of the sentence (probably autogenerated but still)

808

nit: empty line

[drprajap]

minor formatting changes

[drprajap]

In D151731#4385244, @kuhar wrote:

LGTM, thanks for the fixes! Just a few nits.

Thanks for reviewing! Addressed those nits. I do not have merge access, could you please help merge this change?

[kuhar]

In D151731#4385281, @drprajap wrote:

In D151731#4385244, @kuhar wrote:

LGTM, thanks for the fixes! Just a few nits.

Thanks for reviewing! Addressed those nits. I do not have merge access, could you please help merge this change?

Sure, what name and email would you like to use for the commit?

[drprajap]

In D151731#4385300, @kuhar wrote:

In D151731#4385281, @drprajap wrote:

In D151731#4385244, @kuhar wrote:

LGTM, thanks for the fixes! Just a few nits.

Thanks for reviewing! Addressed those nits. I do not have merge access, could you please help merge this change?

Sure, what name and email would you like to use for the commit?

Name: Dimple Prajapati
Email: [e-mail]

Thank you so much!

[kuhar]

Landed in https://reviews.llvm.org/rG8939b5f5d2f30186a72f4ad44480ee9978663998. I changed the commit title and fixed blankspace in the commit message to adhere to MLIR/SPIRV conventions.

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

class SPIRV_CLBinaryOp<string mnemonic, int opcode, Type resultType,
   );
 
   let hasVerifier = 0;
 }
 
 // Base class for OpenCL Binary arithmetic ops where operand types and
 // return type matches.
 class SPIRV_CLBinaryArithmeticOp<string mnemonic, int opcode, Type type,
                                  list<Trait> traits = []> :
   SPIRV_CLBinaryOp<mnemonic, opcode, type, type,
                   traits # [SameOperandsAndResultType]> {
   let assemblyFormat = "operands attr-dict `:` type($result)";
 }
 
 // Base class for OpenCL binary ops.
 class SPIRV_CLTernaryOp<string mnemonic, int opcode, Type resultType,
                       Type operandType, list<Trait> traits = []> :
let description = [{
     #### Example:
     ```mlir
     %2 = spirv.CL.u_min %0, %1 : i32
     %3 = spirv.CL.u_min %0, %1 : vector<3xi16>
     ```
   }];
 }
 
+// -----
+
+def SPIRV_CLPrintfOp : SPIRV_CLOp<"printf", 184, []> {
+  let summary = [{
+    The printf extended instruction writes output to an implementation-
+    defined stream such as stdout under control of the string pointed to by
+    format that specifies how subsequent arguments are converted for output.
+  }];
+
+  let description = [{
+    printf returns 0 if it was executed successfully and -1 otherwise.
+
+    Result Type must be i32.
+
+    Format must be a pointer(constant) to i8. If there are insufficient 
+    arguments for the format, the behavior is undefined. If the format 
+    is exhausted while arguments remain, the excess arguments are evaluated
+    (as always) but are otherwise ignored. The printf instruction returns 
+    when the end of the format string is encountered.
+
+    <!-- End of AutoGen section -->
+
+    #### Example:
+
+    ```mlir
+    %0 = spirv.CL.printf %0 %1 %2 : (!spirv.ptr<i8, UniformConstant>, (i32, i32)) -> i32
+    ```
+  }];
+
+  let arguments = (ins
+    SPIRV_AnyPtr:$format,
+    Variadic<SPIRV_Type>:$arguments
+  );
+  
+   let results = (outs
+    SPIRV_Integer:$result
+  );
+
+  let assemblyFormat = [{
+  $format `,` $arguments  attr-dict `:`  `(` type($format) `,` `(` type($arguments) `)` `)` `->` type($result)
+  }];
+
+  let hasVerifier = 0;
+}
 #endif // MLIR_DIALECT_SPIRV_IR_CL_OPS

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

 }
 
 // CHECK-LABEL: func.func @rintvec(
 func.func @rintvec(%arg0 : vector<3xf16>) -> () {
   // CHECK: spirv.CL.rint {{%.*}} : vector<3xf16>
   %0 = spirv.CL.rint %arg0 : vector<3xf16>
   return
 }
+
+// -----
+
+//===----------------------------------------------------------------------===//
+// spirv.CL.printf
+//===----------------------------------------------------------------------===//
+// CHECK-LABEL: func.func @printf(
+func.func @printf(%arg0 : !spirv.ptr<i8, UniformConstant>, %arg1 : i32, %arg2 : i32) -> i32 {
+  // CHECK: spirv.CL.printf {{%.*}}, {{%.*}}, {{%.*}} : (!spirv.ptr<i8, UniformConstant>, (i32, i32)) -> i32
+  %0 = spirv.CL.printf %arg0, %arg1, %arg2 : (!spirv.ptr<i8, UniformConstant>, (i32, i32)) -> i32
+  return %0 : i32
+}
+