[X86][LegalizeDAG] FPOWI: promote f16 operand (#105775)

Fixes #105747

---------

Co-authored-by: v01dxyz <[email protected]>

Author: v01dXYZ

llvm/lib/Target/X86/X86ISelLowering.cpp

@@ -614,6 +614,7 @@ X86TargetLowering::X86TargetLowering(const X86TargetMachine &TM,
     setOperationAction(ISD::FTAN, VT, Action);
     setOperationAction(ISD::FSQRT, VT, Action);
     setOperationAction(ISD::FPOW, VT, Action);
+    setOperationAction(ISD::FPOWI, VT, Action);
     setOperationAction(ISD::FLOG, VT, Action);
     setOperationAction(ISD::FLOG2, VT, Action);
     setOperationAction(ISD::FLOG10, VT, Action);

llvm/test/CodeGen/X86/fp16-libcalls.ll

@@ -926,6 +926,77 @@ define void @test_half_pow(half %a0, half %a1, ptr %p0) nounwind {
   ret void
 }
 
+define void @test_half_powi(half %a0, i32 %a1, ptr %p0) nounwind {
+; F16C-LABEL: test_half_powi:
+; F16C:       # %bb.0:
+; F16C-NEXT:    pushq %rbx
+; F16C-NEXT:    movq %rsi, %rbx
+; F16C-NEXT:    vpextrw $0, %xmm0, %eax
+; F16C-NEXT:    vmovd %eax, %xmm0
+; F16C-NEXT:    vcvtph2ps %xmm0, %xmm0
+; F16C-NEXT:    callq __powisf2@PLT
+; F16C-NEXT:    vcvtps2ph $4, %xmm0, %xmm0
+; F16C-NEXT:    vmovd %xmm0, %eax
+; F16C-NEXT:    movw %ax, (%rbx)
+; F16C-NEXT:    popq %rbx
+; F16C-NEXT:    retq
+;
+; FP16-LABEL: test_half_powi:
+; FP16:       # %bb.0:
+; FP16-NEXT:    pushq %rbx
+; FP16-NEXT:    movq %rsi, %rbx
+; FP16-NEXT:    vcvtsh2ss %xmm0, %xmm0, %xmm0
+; FP16-NEXT:    callq __powisf2@PLT
+; FP16-NEXT:    vcvtss2sh %xmm0, %xmm0, %xmm0
+; FP16-NEXT:    vmovsh %xmm0, (%rbx)
+; FP16-NEXT:    popq %rbx
+; FP16-NEXT:    retq
+;
+; X64-LABEL: test_half_powi:
+; X64:       # %bb.0:
+; X64-NEXT:    pushq %rbp
+; X64-NEXT:    pushq %rbx
+; X64-NEXT:    pushq %rax
+; X64-NEXT:    movq %rsi, %rbx
+; X64-NEXT:    movl %edi, %ebp
+; X64-NEXT:    callq __extendhfsf2@PLT
+; X64-NEXT:    movl %ebp, %edi
+; X64-NEXT:    callq __powisf2@PLT
+; X64-NEXT:    callq __truncsfhf2@PLT
+; X64-NEXT:    pextrw $0, %xmm0, %eax
+; X64-NEXT:    movw %ax, (%rbx)
+; X64-NEXT:    addq $8, %rsp
+; X64-NEXT:    popq %rbx
+; X64-NEXT:    popq %rbp
+; X64-NEXT:    retq
+;
+; X86-LABEL: test_half_powi:
+; X86:       # %bb.0:
+; X86-NEXT:    pushl %edi
+; X86-NEXT:    pushl %esi
+; X86-NEXT:    subl $20, %esp
+; X86-NEXT:    pinsrw $0, {{[0-9]+}}(%esp), %xmm0
+; X86-NEXT:    movl {{[0-9]+}}(%esp), %esi
+; X86-NEXT:    movl {{[0-9]+}}(%esp), %edi
+; X86-NEXT:    pextrw $0, %xmm0, %eax
+; X86-NEXT:    movw %ax, (%esp)
+; X86-NEXT:    calll __extendhfsf2
+; X86-NEXT:    movl %edi, {{[0-9]+}}(%esp)
+; X86-NEXT:    fstps (%esp)
+; X86-NEXT:    calll __powisf2
+; X86-NEXT:    fstps (%esp)
+; X86-NEXT:    calll __truncsfhf2
+; X86-NEXT:    pextrw $0, %xmm0, %eax
+; X86-NEXT:    movw %ax, (%esi)
+; X86-NEXT:    addl $20, %esp
+; X86-NEXT:    popl %esi
+; X86-NEXT:    popl %edi
+; X86-NEXT:    retl
+  %res = call half @llvm.powi.half(half %a0, i32 %a1)
+  store half %res, ptr %p0, align 2
+  ret void
+}
+
 define void @test_half_rint(half %a0, ptr %p0) nounwind {
 ; F16C-LABEL: test_half_rint:
 ; F16C:       # %bb.0: