[llvm] [NVPTX] Add pm_event intrinsics (PR #141278)

[via llvm-commits]

llvmbot wrote:


<!--LLVM PR SUMMARY COMMENT-->

@llvm/pr-subscribers-backend-nvptx

Author: Durgadoss R (durga4github)

<details>
<summary>Changes</summary>

This patch adds both `idx` and `mask` variants of
pm_event intrinsics.

---
Full diff: https://github.com/llvm/llvm-project/pull/141278.diff


5 Files Affected:

- (modified) llvm/docs/NVPTXUsage.rst (+32) 
- (modified) llvm/include/llvm/IR/IntrinsicsNVVM.td (+12) 
- (modified) llvm/lib/Target/NVPTX/NVPTXIntrinsics.td (+11) 
- (added) llvm/test/CodeGen/NVPTX/pm-event-invalid.ll (+10) 
- (added) llvm/test/CodeGen/NVPTX/pm-event.ll (+16) 


``````````diff
diff --git a/llvm/docs/NVPTXUsage.rst b/llvm/docs/NVPTXUsage.rst
index 8bb0f2ed17c32..9d108a98210b0 100644
--- a/llvm/docs/NVPTXUsage.rst
+++ b/llvm/docs/NVPTXUsage.rst
@@ -1868,6 +1868,38 @@ If the request failed, the behavior of these intrinsics is undefined.
 
 For more information, refer `PTX ISA <https://docs.nvidia.com/cuda/parallel-thread-execution/?a#parallel-synchronization-and-communication-instructions-clusterlaunchcontrol-query-cancel>`__.
 
+Perf Monitor Event Intrinsics
+-----------------------------
+
+'``llvm.nvvm.pm.event.[idx|mask]``' Intrinsics
+^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+
+Syntax:
+"""""""
+
+.. code-block:: llvm
+
+    declare void @llvm.nvvm.pm.event.idx(i32 immarg %idx_val)
+    declare void @llvm.nvvm.pm.event.mask(i16 immarg %mask_val)
+
+Overview:
+"""""""""
+
+The '``llvm.nvvm.pm.event.*``' intrinsics trigger one or more
+performance monitor events.
+
+The ``idx`` variant triggers a single performance monitor event
+indexed by the immediate operand ``%idx_val`` in the range
+[0, 16). When the ``%idx_val`` is not within the range, it may
+raise an error from the verifier.
+
+The ``mask`` variant triggers one or more of the performance
+monitor events. Each bit in the 16-bit immediate operand
+``%mask_val`` controls an event.
+
+For more information on the pmevent instructions, refer to the PTX ISA
+`<https://docs.nvidia.com/cuda/parallel-thread-execution/index.html#miscellaneous-instructions-pmevent>`_.
+
 Other Intrinsics
 ----------------
 
diff --git a/llvm/include/llvm/IR/IntrinsicsNVVM.td b/llvm/include/llvm/IR/IntrinsicsNVVM.td
index 91e7d188c8533..826b87818fa60 100644
--- a/llvm/include/llvm/IR/IntrinsicsNVVM.td
+++ b/llvm/include/llvm/IR/IntrinsicsNVVM.td
@@ -768,6 +768,18 @@ let TargetPrefix = "nvvm" in {
       DefaultAttrsIntrinsic<[], [llvm_i32_ty],
                             [IntrConvergent, IntrNoMem, IntrHasSideEffects]>;
 
+  // Performance Monitor Events (pm events) intrinsics
+  // The imm-argument to the _idx variant must be
+  // within the range [0, 16).
+  def int_nvvm_pm_event_idx : NVVMBuiltin,
+      DefaultAttrsIntrinsic<[], [llvm_i32_ty],
+                [IntrConvergent, IntrNoMem, IntrHasSideEffects,
+                 ImmArg<ArgIndex<0>>, Range<ArgIndex<0>, 0, 16>]>;
+  def int_nvvm_pm_event_mask : NVVMBuiltin,
+      DefaultAttrsIntrinsic<[], [llvm_i16_ty],
+                [IntrConvergent, IntrNoMem, IntrHasSideEffects,
+                 ImmArg<ArgIndex<0>>]>;
+
 //
 // Min Max
 //
diff --git a/llvm/lib/Target/NVPTX/NVPTXIntrinsics.td b/llvm/lib/Target/NVPTX/NVPTXIntrinsics.td
index 8fb5884fa2a20..2e0e52c2a5a1f 100644
--- a/llvm/lib/Target/NVPTX/NVPTXIntrinsics.td
+++ b/llvm/lib/Target/NVPTX/NVPTXIntrinsics.td
@@ -7172,6 +7172,17 @@ defm INT_SET_MAXNREG_DEC : SET_MAXNREG<"dec", int_nvvm_setmaxnreg_dec_sync_align
 
 } // isConvergent
 
+let hasSideEffects = 1 in {
+// Performance Monitor events
+def INT_PM_EVENT_IDX :  NVPTXInst<(outs), (ins i32imm:$idx),
+                        "pmevent $idx;",
+                        [(int_nvvm_pm_event_idx timm:$idx)]>;
+def INT_PM_EVENT_MASK : NVPTXInst<(outs), (ins i16imm:$mask),
+                        "pmevent.mask $mask;",
+                        [(int_nvvm_pm_event_mask timm:$mask)]>,
+                        Requires<[hasSM<20>, hasPTX<30>]>;
+} // hasSideEffects
+
 //
 // WGMMA fence instructions
 //
diff --git a/llvm/test/CodeGen/NVPTX/pm-event-invalid.ll b/llvm/test/CodeGen/NVPTX/pm-event-invalid.ll
new file mode 100644
index 0000000000000..11b333422a49f
--- /dev/null
+++ b/llvm/test/CodeGen/NVPTX/pm-event-invalid.ll
@@ -0,0 +1,10 @@
+; RUN: not llc < %s -mtriple=nvptx64 -mcpu=sm_20 -o /dev/null 2>&1 | FileCheck %s
+
+declare void @llvm.nvvm.pm.event.idx(i32 immarg %idx)
+
+define void @test_invalid_pm_event() {
+  ; CHECK: immarg value 16 out of range [0, 16)
+  call void @llvm.nvvm.pm.event.idx(i32 16)
+
+  ret void
+}
diff --git a/llvm/test/CodeGen/NVPTX/pm-event.ll b/llvm/test/CodeGen/NVPTX/pm-event.ll
new file mode 100644
index 0000000000000..83ed450c77b3d
--- /dev/null
+++ b/llvm/test/CodeGen/NVPTX/pm-event.ll
@@ -0,0 +1,16 @@
+; RUN: llc < %s -mtriple=nvptx64 -mcpu=sm_20 | FileCheck %s
+; RUN: %if ptxas %{ llc < %s -mtriple=nvptx64 -mcpu=sm_20 | %ptxas-verify %}
+
+declare void @llvm.nvvm.pm.event.idx(i32 %idx)
+declare void @llvm.nvvm.pm.event.mask(i16 %mask)
+
+; CHECK-LABEL: test_pm_event
+define void @test_pm_event() {
+  ; CHECK: pmevent 15;
+  call void @llvm.nvvm.pm.event.idx(i32 15)
+
+  ; CHECK: pmevent.mask 255;
+  call void @llvm.nvvm.pm.event.mask(i16 u0xff)
+
+  ret void
+}

``````````

</details>


https://github.com/llvm/llvm-project/pull/141278