[X86][LegalizeDAG] Legalize FPOWI (f16) with Promote

Instead of defaulting to Expand.

Without that, since Expand is not implemented for FPOWI, it
fallthroughs to Libcall. As there are no f16 libcalls, the program
aborts when asserts are enabled.

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

@@ -932,12 +932,9 @@ define void @test_half_powi(half %a0, i32 %a1, ptr %p0) nounwind {
 ; F16C-NEXT:    pushq %rbx
 ; F16C-NEXT:    movq %rsi, %rbx
 ; F16C-NEXT:    vpextrw $0, %xmm0, %eax
-; F16C-NEXT:    vcvtsi2ss %edi, %xmm1, %xmm0
-; F16C-NEXT:    vcvtps2ph $4, %xmm0, %xmm0
-; F16C-NEXT:    vcvtph2ps %xmm0, %xmm1
 ; F16C-NEXT:    vmovd %eax, %xmm0
 ; F16C-NEXT:    vcvtph2ps %xmm0, %xmm0
-; F16C-NEXT:    callq powf@PLT
+; F16C-NEXT:    callq __powisf2@PLT
 ; F16C-NEXT:    vcvtps2ph $4, %xmm0, %xmm0
 ; F16C-NEXT:    vmovd %xmm0, %eax
 ; F16C-NEXT:    movw %ax, (%rbx)
@@ -949,9 +946,7 @@ define void @test_half_powi(half %a0, i32 %a1, ptr %p0) nounwind {
 ; FP16-NEXT:    pushq %rbx
 ; FP16-NEXT:    movq %rsi, %rbx
 ; FP16-NEXT:    vcvtsh2ss %xmm0, %xmm0, %xmm0
-; FP16-NEXT:    vcvtsi2sh %edi, %xmm1, %xmm1
-; FP16-NEXT:    vcvtsh2ss %xmm1, %xmm1, %xmm1
-; FP16-NEXT:    callq powf@PLT
+; FP16-NEXT:    callq __powisf2@PLT
 ; FP16-NEXT:    vcvtss2sh %xmm0, %xmm0, %xmm0
 ; FP16-NEXT:    vmovsh %xmm0, (%rbx)
 ; FP16-NEXT:    popq %rbx
@@ -965,15 +960,8 @@ define void @test_half_powi(half %a0, i32 %a1, ptr %p0) nounwind {
 ; X64-NEXT:    movq %rsi, %rbx
 ; X64-NEXT:    movl %edi, %ebp
 ; X64-NEXT:    callq __extendhfsf2@PLT
-; X64-NEXT:    movss %xmm0, {{[-0-9]+}}(%r{{[sb]}}p) # 4-byte Spill
-; X64-NEXT:    xorps %xmm0, %xmm0
-; X64-NEXT:    cvtsi2ss %ebp, %xmm0
-; X64-NEXT:    callq __truncsfhf2@PLT
-; X64-NEXT:    callq __extendhfsf2@PLT
-; X64-NEXT:    movaps %xmm0, %xmm1
-; X64-NEXT:    movd {{[-0-9]+}}(%r{{[sb]}}p), %xmm0 # 4-byte Folded Reload
-; X64-NEXT:    # xmm0 = mem[0],zero,zero,zero
-; X64-NEXT:    callq powf@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)
@@ -984,33 +972,25 @@ define void @test_half_powi(half %a0, i32 %a1, ptr %p0) nounwind {
 ;
 ; X86-LABEL: test_half_powi:
 ; X86:       # %bb.0:
+; X86-NEXT:    pushl %edi
 ; X86-NEXT:    pushl %esi
-; X86-NEXT:    subl $56, %esp
+; X86-NEXT:    subl $20, %esp
 ; X86-NEXT:    pinsrw $0, {{[0-9]+}}(%esp), %xmm0
-; X86-NEXT:    movdqa %xmm0, {{[-0-9]+}}(%e{{[sb]}}p) # 16-byte Spill
 ; X86-NEXT:    movl {{[0-9]+}}(%esp), %esi
-; X86-NEXT:    xorps %xmm0, %xmm0
-; X86-NEXT:    cvtsi2ssl {{[0-9]+}}(%esp), %xmm0
-; X86-NEXT:    movss %xmm0, (%esp)
-; X86-NEXT:    calll __truncsfhf2
-; X86-NEXT:    pextrw $0, %xmm0, %eax
-; X86-NEXT:    movw %ax, (%esp)
-; X86-NEXT:    calll __extendhfsf2
-; X86-NEXT:    fstpt {{[-0-9]+}}(%e{{[sb]}}p) # 10-byte Folded Spill
-; X86-NEXT:    movdqa {{[-0-9]+}}(%e{{[sb]}}p), %xmm0 # 16-byte Reload
+; 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:    fldt {{[-0-9]+}}(%e{{[sb]}}p) # 10-byte Folded Reload
-; X86-NEXT:    fstps {{[0-9]+}}(%esp)
-; X86-NEXT:    calll powf
+; 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 $56, %esp
+; 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