[llvm] AArch64: Set FMAXIMUMNUM and FMINIMUMNUM as Promote if not fullfp16 (PR #135708)

[via llvm-commits]

llvmbot wrote:


<!--LLVM PR SUMMARY COMMENT-->

@llvm/pr-subscribers-backend-aarch64

Author: YunQiang Su (wzssyqa)

<details>
<summary>Changes</summary>

Since Promote will emit FP_EXTEND, the result of it will never be sNaN, so we don't need worry about duplicated of FCANONICALIZE in expandFMINIMUMNUM_FMAXIMUMNUM.

---
Full diff: https://github.com/llvm/llvm-project/pull/135708.diff


2 Files Affected:

- (modified) llvm/lib/Target/AArch64/AArch64ISelLowering.cpp (+2) 
- (added) llvm/test/CodeGen/AArch64/fminmax-f16-promote.ll (+28) 


``````````diff
diff --git a/llvm/lib/Target/AArch64/AArch64ISelLowering.cpp b/llvm/lib/Target/AArch64/AArch64ISelLowering.cpp
index 830ec6886e6bc..bea8087750d6e 100644
--- a/llvm/lib/Target/AArch64/AArch64ISelLowering.cpp
+++ b/llvm/lib/Target/AArch64/AArch64ISelLowering.cpp
@@ -795,6 +795,8 @@ AArch64TargetLowering::AArch64TargetLowering(const TargetMachine &TM,
              ISD::FMAXNUM,
              ISD::FMINIMUM,
              ISD::FMAXIMUM,
+             ISD::FMINIMUMNUM,
+             ISD::FMAXIMUMNUM,
              ISD::FCANONICALIZE,
              ISD::STRICT_FADD,
              ISD::STRICT_FSUB,
diff --git a/llvm/test/CodeGen/AArch64/fminmax-f16-promote.ll b/llvm/test/CodeGen/AArch64/fminmax-f16-promote.ll
new file mode 100644
index 0000000000000..abd0a8e6591ec
--- /dev/null
+++ b/llvm/test/CodeGen/AArch64/fminmax-f16-promote.ll
@@ -0,0 +1,28 @@
+; NOTE: Assertions have been autogenerated by utils/update_llc_test_checks.py UTC_ARGS: --version 5
+; RUN: llc -mtriple=aarch64 -verify-machineinstrs %s -o - | FileCheck %s
+
+define half @min(half noundef %a, half noundef %b) {
+; CHECK-LABEL: min:
+; CHECK:       // %bb.0: // %entry
+; CHECK-NEXT:    fcvt s1, h1
+; CHECK-NEXT:    fcvt s0, h0
+; CHECK-NEXT:    fminnm s0, s0, s1
+; CHECK-NEXT:    fcvt h0, s0
+; CHECK-NEXT:    ret
+entry:
+  %0 = tail call half @llvm.minimumnum.f16(half %a, half %b)
+  ret half %0
+}
+
+define half @max(half noundef %a, half noundef %b) {
+; CHECK-LABEL: max:
+; CHECK:       // %bb.0: // %entry
+; CHECK-NEXT:    fcvt s1, h1
+; CHECK-NEXT:    fcvt s0, h0
+; CHECK-NEXT:    fmaxnm s0, s0, s1
+; CHECK-NEXT:    fcvt h0, s0
+; CHECK-NEXT:    ret
+entry:
+  %0 = tail call half @llvm.maximumnum.f16(half %a, half %b)
+  ret half %0
+}

``````````

</details>


https://github.com/llvm/llvm-project/pull/135708