[llvm-branch-commits] [llvm] [AMDGPU] Mark `amdgcn_tanh` as canonicalized (PR #150059)

[Shilei Tian via llvm-branch-commits]

https://github.com/shiltian created https://github.com/llvm/llvm-project/pull/150059

Co-authored-by: Mekhanoshin, Stanislav <Stanislav.Mekhanoshin at amd.com>

>From cff95bce02ac454110effce11dda00e8757eaeb1 Mon Sep 17 00:00:00 2001
From: Shilei Tian <i at tianshilei.me>
Date: Tue, 22 Jul 2025 12:38:12 -0400
Subject: [PATCH] [AMDGPU] Mark `amdgcn_tanh` as canonicalized

Co-authored-by: Mekhanoshin, Stanislav <Stanislav.Mekhanoshin at amd.com>
---
 llvm/lib/Target/AMDGPU/SIISelLowering.cpp     |  1 +
 .../AMDGPU/fcanonicalize-elimination.bf16.ll  | 44 +++++++++++++++++++
 2 files changed, 45 insertions(+)
 create mode 100644 llvm/test/CodeGen/AMDGPU/fcanonicalize-elimination.bf16.ll

diff --git a/llvm/lib/Target/AMDGPU/SIISelLowering.cpp b/llvm/lib/Target/AMDGPU/SIISelLowering.cpp
index bc0fd8d4e814b..d65c3ae76566b 100644
--- a/llvm/lib/Target/AMDGPU/SIISelLowering.cpp
+++ b/llvm/lib/Target/AMDGPU/SIISelLowering.cpp
@@ -13633,6 +13633,7 @@ bool SITargetLowering::isCanonicalized(SelectionDAG &DAG, SDValue Op,
     case Intrinsic::amdgcn_rcp_legacy:
     case Intrinsic::amdgcn_rsq_legacy:
     case Intrinsic::amdgcn_trig_preop:
+    case Intrinsic::amdgcn_tanh:
     case Intrinsic::amdgcn_log:
     case Intrinsic::amdgcn_exp2:
     case Intrinsic::amdgcn_sqrt:
diff --git a/llvm/test/CodeGen/AMDGPU/fcanonicalize-elimination.bf16.ll b/llvm/test/CodeGen/AMDGPU/fcanonicalize-elimination.bf16.ll
new file mode 100644
index 0000000000000..85e7038b38563
--- /dev/null
+++ b/llvm/test/CodeGen/AMDGPU/fcanonicalize-elimination.bf16.ll
@@ -0,0 +1,44 @@
+; NOTE: Assertions have been autogenerated by utils/update_llc_test_checks.py UTC_ARGS: --version 5
+; RUN: llc -mtriple=amdgcn-amd-amdhsa -mcpu=gfx1250 %s -o - | FileCheck -check-prefix=GCN %s
+
+define float @test_canonicalize_amdgcn_tanh_f32(float %a) {
+; GCN-LABEL: test_canonicalize_amdgcn_tanh_f32:
+; GCN:       ; %bb.0:
+; GCN-NEXT:    s_wait_loadcnt_dscnt 0x0
+; GCN-NEXT:    s_wait_kmcnt 0x0
+; GCN-NEXT:    v_tanh_f32_e32 v0, v0
+; GCN-NEXT:    s_set_pc_i64 s[30:31]
+  %tanh = call float @llvm.amdgcn.tanh.f32(float %a)
+  %canonicalized = call float @llvm.canonicalize.f32(float %tanh)
+  ret float %canonicalized
+}
+
+define bfloat @test_canonicalize_amdgcn_tanh_bf16(bfloat %a) {
+; GCN-LABEL: test_canonicalize_amdgcn_tanh_bf16:
+; GCN:       ; %bb.0:
+; GCN-NEXT:    s_wait_loadcnt_dscnt 0x0
+; GCN-NEXT:    s_wait_kmcnt 0x0
+; GCN-NEXT:    v_tanh_bf16_e32 v0, v0
+; GCN-NEXT:    v_nop
+; GCN-NEXT:    s_delay_alu instid0(TRANS32_DEP_1) | instskip(NEXT) | instid1(VALU_DEP_1)
+; GCN-NEXT:    v_lshlrev_b32_e32 v0, 16, v0
+; GCN-NEXT:    v_max_num_f32_e32 v0, v0, v0
+; GCN-NEXT:    s_delay_alu instid0(VALU_DEP_1)
+; GCN-NEXT:    v_cvt_pk_bf16_f32 v0, v0, s0
+; GCN-NEXT:    s_set_pc_i64 s[30:31]
+  %tanh = call bfloat @llvm.amdgcn.tanh.bf16(bfloat %a)
+  %canonicalized = call bfloat @llvm.canonicalize.bf16(bfloat %tanh)
+  ret bfloat %canonicalized
+}
+
+define half @test_canonicalize_amdgcn_tanh_f16(half %a) {
+; GCN-LABEL: test_canonicalize_amdgcn_tanh_f16:
+; GCN:       ; %bb.0:
+; GCN-NEXT:    s_wait_loadcnt_dscnt 0x0
+; GCN-NEXT:    s_wait_kmcnt 0x0
+; GCN-NEXT:    v_tanh_f16_e32 v0, v0
+; GCN-NEXT:    s_set_pc_i64 s[30:31]
+  %tanh = call half @llvm.amdgcn.tanh.f16(half %a)
+  %canonicalized = call half @llvm.canonicalize.f16(half %tanh)
+  ret half %canonicalized
+}