fix: simplify redundant softmax version condition

[andrewwhitecdw]

This PR addresses the following issue in transformer_engine/common/fused_attn/fused_attn.cpp: simplify redundant softmax version condition.

Changes

• transformer_engine/common/fused_attn/fused_attn.cpp: simplify redundant softmax version condition.

Details

--- a/transformer_engine/common/fused_attn/fused_attn.cpp
+++ b/transformer_engine/common/fused_attn/fused_attn.cpp
@@ -1,6 +1,5 @@
-        // softmax type
-        // pre-9.13.1: vanilla
-        // 9.13.1+: vanilla, off-by-one, learnable
-        (cudnn_runtime_version >= 91301 ||
-         (cudnn_runtime_version < 91301 &&
-          softmax_type == NVTE_Softmax_Type::NVTE_VANILLA_SOFTMAX)) &&
+        // softmax type
+        // pre-9.13.1: vanilla
+        // 9.13.1+: vanilla, off-by-one, learnable
+        (cudnn_runtime_version >= 91301 ||
+         softmax_type == NVTE_Softmax_Type::NVTE_VANILLA_SOFTMAX) &&

Tests

Let me know if you want tests added for this fix or not.

[greptile-apps]

Greptile Summary

The PR simplifies a redundant cuDNN-version condition in fused-attention backend selection without changing its Boolean behavior.

• Removes the unnecessary cudnn_runtime_version < 91301 subcondition.
• Preserves vanilla softmax support on older cuDNN versions and all supported softmax types on cuDNN 9.13.1 or newer.

Confidence Score: 5/5

The PR appears safe to merge.

No blocking failure remains.

Important Files Changed

Filename	Overview
transformer_engine/common/fused_attn/fused_attn.cpp	Simplifies the softmax eligibility expression to its logically equivalent form without altering backend selection.

_{Reviews (2): Last reviewed commit: "fix: simplify redundant softmax version ..." | Re-trigger Greptile}

[cyanguwa]

Please fix the DCO for this PR. Thanks.