[ARM] Promote various fp16 math routines

[dmgreen]

Summary

We promote these to floats, so as to use the float libcalls. copysign is the exception, which gets expanded.

[SjoerdMeijer]

Looks okay to me

Is fp16-full.ll a new file? Perhaps I'm missing something, but I don't see it. Please note that we have fp16-instructions.ll which test all fp16 instructions.

llvm/lib/Target/ARM/ARMISelLowering.cpp

if (!Subtarget->isFPOnlySP()) {
       setOperationAction(ISD::FMINNUM, MVT::f64, Legal);
       setOperationAction(ISD::FMAXNUM, MVT::f64, Legal);
     }
   }
 
   // FP16 often need to be promoted to call lib functions
   if (Subtarget->hasFullFP16()) {
     setOperationAction(ISD::FREM, MVT::f16, Promote);
+    setOperationAction(ISD::FCOPYSIGN, MVT::f16, Expand);
+    setOperationAction(ISD::FSIN, MVT::f16, Promote);
+    setOperationAction(ISD::FCOS, MVT::f16, Promote);
+    setOperationAction(ISD::FSINCOS, MVT::f16, Promote);
+    setOperationAction(ISD::FPOWI, MVT::f16, Promote);
+    setOperationAction(ISD::FPOW, MVT::f16, Promote);
+    setOperationAction(ISD::FEXP, MVT::f16, Promote);
+    setOperationAction(ISD::FEXP2, MVT::f16, Promote);
+    setOperationAction(ISD::FLOG, MVT::f16, Promote);
+    setOperationAction(ISD::FLOG10, MVT::f16, Promote);
+    setOperationAction(ISD::FLOG2, MVT::f16, Promote);
   }
 
   if (Subtarget->hasNEON()) {
     // vmin and vmax aren't available in a scalar form, so we use
     // a NEON instruction with an undef lane instead.
     setOperationAction(ISD::FMINIMUM, MVT::f16, Legal);
     setOperationAction(ISD::FMAXIMUM, MVT::f16, Legal);
     setOperationAction(ISD::FMINIMUM, MVT::f32, Legal);

llvm/test/CodeGen/ARM/fp16-full.ll

 ; CHECK-NEXT:    vstr.16 s0, [r0]
 ; CHECK-NEXT:    bx lr
   %a = load half, half* %p, align 2
   %r = call half @llvm.sqrt.f16(half %a)
   store half %r, half* %p
   ret void
 }
 
-; FIXME
-;define void @test_fpowi(half* %p, i32 %b) {
-;  %a = load half, half* %p, align 2
-;  %r = call half @llvm.powi.f16(half %a, i32 %b)
-;  store half %r, half* %p
-;  ret void
-;}
+define void @test_fpowi(half* %p, i32 %b) {
+; CHECK-LABEL: test_fpowi:
+; CHECK:         .save {r4, lr}
+; CHECK-NEXT:    push {r4, lr}
+; CHECK-NEXT:    vldr.16 s0, [r0]
+; CHECK-NEXT:    mov r4, r0
+; CHECK-NEXT:    mov r0, r1
+; CHECK-NEXT:    vcvtb.f32.f16 s0, s0
+; CHECK-NEXT:    bl __powisf2
+; CHECK-NEXT:    vcvtb.f16.f32 s0, s0
+; CHECK-NEXT:    vstr.16 s0, [r4]
+; CHECK-NEXT:    pop {r4, pc}
+  %a = load half, half* %p, align 2
+  %r = call half @llvm.powi.f16(half %a, i32 %b)
+  store half %r, half* %p
+  ret void
+}
 
-; FIXME
-;define void @test_sin(half* %p) {
-;  %a = load half, half* %p, align 2
-;  %r = call half @llvm.sin.f16(half %a)
-;  store half %r, half* %p
-;  ret void
-;}
+define void @test_sin(half* %p) {
+; CHECK-LABEL: test_sin:
+; CHECK:         .save {r4, lr}
+; CHECK-NEXT:    push {r4, lr}
+; CHECK-NEXT:    vldr.16 s0, [r0]
+; CHECK-NEXT:    mov r4, r0
+; CHECK-NEXT:    vcvtb.f32.f16 s0, s0
+; CHECK-NEXT:    bl sinf
+; CHECK-NEXT:    vcvtb.f16.f32 s0, s0
+; CHECK-NEXT:    vstr.16 s0, [r4]
+; CHECK-NEXT:    pop {r4, pc}
+  %a = load half, half* %p, align 2
+  %r = call half @llvm.sin.f16(half %a)
+  store half %r, half* %p
+  ret void
+}
 
-; FIXME
-;define void @test_cos(half* %p) {
-;  %a = load half, half* %p, align 2
-;  %r = call half @llvm.cos.f16(half %a)
-;  store half %r, half* %p
-;  ret void
-;}
+define void @test_cos(half* %p) {
+; CHECK-LABEL: test_cos:
+; CHECK:         .save {r4, lr}
+; CHECK-NEXT:    push {r4, lr}
+; CHECK-NEXT:    vldr.16 s0, [r0]
+; CHECK-NEXT:    mov r4, r0
+; CHECK-NEXT:    vcvtb.f32.f16 s0, s0
+; CHECK-NEXT:    bl cosf
+; CHECK-NEXT:    vcvtb.f16.f32 s0, s0
+; CHECK-NEXT:    vstr.16 s0, [r4]
+; CHECK-NEXT:    pop {r4, pc}
+  %a = load half, half* %p, align 2
+  %r = call half @llvm.cos.f16(half %a)
+  store half %r, half* %p
+  ret void
+}
 
-; FIXME
-;define void @test_pow(half* %p, half* %q) {
-;  %a = load half, half* %p, align 2
-;  %b = load half, half* %q, align 2
-;  %r = call half @llvm.pow.f16(half %a, half %b)
-;  store half %r, half* %p
-;  ret void
-;}
+define void @test_pow(half* %p, half* %q) {
+; CHECK-LABEL: test_pow:
+; CHECK:         .save {r4, lr}
+; CHECK-NEXT:    push {r4, lr}
+; CHECK-NEXT:    vldr.16 s2, [r1]
+; CHECK-NEXT:    vldr.16 s0, [r0]
+; CHECK-NEXT:    mov r4, r0
+; CHECK-NEXT:    vcvtb.f32.f16 s0, s0
+; CHECK-NEXT:    vcvtb.f32.f16 s1, s2
+; CHECK-NEXT:    bl powf
+; CHECK-NEXT:    vcvtb.f16.f32 s0, s0
+; CHECK-NEXT:    vstr.16 s0, [r4]
+; CHECK-NEXT:    pop {r4, pc}
+  %a = load half, half* %p, align 2
+  %b = load half, half* %q, align 2
+  %r = call half @llvm.pow.f16(half %a, half %b)
+  store half %r, half* %p
+  ret void
+}
 
-; FIXME
-;define void @test_exp(half* %p) {
-;  %a = load half, half* %p, align 2
-;  %r = call half @llvm.exp.f16(half %a)
-;  store half %r, half* %p
-;  ret void
-;}
+define void @test_exp(half* %p) {
+; CHECK-LABEL: test_exp:
+; CHECK:         .save {r4, lr}
+; CHECK-NEXT:    push {r4, lr}
+; CHECK-NEXT:    vldr.16 s0, [r0]
+; CHECK-NEXT:    mov r4, r0
+; CHECK-NEXT:    vcvtb.f32.f16 s0, s0
+; CHECK-NEXT:    bl expf
+; CHECK-NEXT:    vcvtb.f16.f32 s0, s0
+; CHECK-NEXT:    vstr.16 s0, [r4]
+; CHECK-NEXT:    pop {r4, pc}
+  %a = load half, half* %p, align 2
+  %r = call half @llvm.exp.f16(half %a)
+  store half %r, half* %p
+  ret void
+}
 
-; FIXME
-;define void @test_exp2(half* %p) {
-;  %a = load half, half* %p, align 2
-;  %r = call half @llvm.exp2.f16(half %a)
-;  store half %r, half* %p
-;  ret void
-;}
+define void @test_exp2(half* %p) {
+; CHECK-LABEL: test_exp2:
+; CHECK:         .save {r4, lr}
+; CHECK-NEXT:    push {r4, lr}
+; CHECK-NEXT:    vldr.16 s0, [r0]
+; CHECK-NEXT:    mov r4, r0
+; CHECK-NEXT:    vcvtb.f32.f16 s0, s0
+; CHECK-NEXT:    bl exp2f
+; CHECK-NEXT:    vcvtb.f16.f32 s0, s0
+; CHECK-NEXT:    vstr.16 s0, [r4]
+; CHECK-NEXT:    pop {r4, pc}
+  %a = load half, half* %p, align 2
+  %r = call half @llvm.exp2.f16(half %a)
+  store half %r, half* %p
+  ret void
+}
 
-; FIXME
-;define void @test_log(half* %p) {
-;  %a = load half, half* %p, align 2
-;  %r = call half @llvm.log.f16(half %a)
-;  store half %r, half* %p
-;  ret void
-;}
+define void @test_log(half* %p) {
+; CHECK-LABEL: test_log:
+; CHECK:         .save {r4, lr}
+; CHECK-NEXT:    push {r4, lr}
+; CHECK-NEXT:    vldr.16 s0, [r0]
+; CHECK-NEXT:    mov r4, r0
+; CHECK-NEXT:    vcvtb.f32.f16 s0, s0
+; CHECK-NEXT:    bl logf
+; CHECK-NEXT:    vcvtb.f16.f32 s0, s0
+; CHECK-NEXT:    vstr.16 s0, [r4]
+; CHECK-NEXT:    pop {r4, pc}
+  %a = load half, half* %p, align 2
+  %r = call half @llvm.log.f16(half %a)
+  store half %r, half* %p
+  ret void
+}
 
-; FIXME
-;define void @test_log10(half* %p) {
-;  %a = load half, half* %p, align 2
-;  %r = call half @llvm.log10.f16(half %a)
-;  store half %r, half* %p
-;  ret void
-;}
+define void @test_log10(half* %p) {
+; CHECK-LABEL: test_log10:
+; CHECK:         .save {r4, lr}
+; CHECK-NEXT:    push {r4, lr}
+; CHECK-NEXT:    vldr.16 s0, [r0]
+; CHECK-NEXT:    mov r4, r0
+; CHECK-NEXT:    vcvtb.f32.f16 s0, s0
+; CHECK-NEXT:    bl log10f
+; CHECK-NEXT:    vcvtb.f16.f32 s0, s0
+; CHECK-NEXT:    vstr.16 s0, [r4]
+; CHECK-NEXT:    pop {r4, pc}
+  %a = load half, half* %p, align 2
+  %r = call half @llvm.log10.f16(half %a)
+  store half %r, half* %p
+  ret void
+}
 
-; FIXME
-;define void @test_log2(half* %p) {
-;  %a = load half, half* %p, align 2
-;  %r = call half @llvm.log2.f16(half %a)
-;  store half %r, half* %p
-;  ret void
-;}
+define void @test_log2(half* %p) {
+; CHECK-LABEL: test_log2:
+; CHECK:         .save {r4, lr}
+; CHECK-NEXT:    push {r4, lr}
+; CHECK-NEXT:    vldr.16 s0, [r0]
+; CHECK-NEXT:    mov r4, r0
+; CHECK-NEXT:    vcvtb.f32.f16 s0, s0
+; CHECK-NEXT:    bl log2f
+; CHECK-NEXT:    vcvtb.f16.f32 s0, s0
+; CHECK-NEXT:    vstr.16 s0, [r4]
+; CHECK-NEXT:    pop {r4, pc}
+  %a = load half, half* %p, align 2
+  %r = call half @llvm.log2.f16(half %a)
+  store half %r, half* %p
+  ret void
+}
 
 ; FIXME
 ;define void @test_fma(half* %p, half* %q, half* %r) {
 ;  %a = load half, half* %p, align 2
 ;  %b = load half, half* %q, align 2
 ;  %c = load half, half* %r, align 2
 ;  %v = call half @llvm.fma.f16(half %a, half %b, half %c)
 ;  store half %v, half* %p

 ; CHECK-NEXT:    bx lr
   %a = load half, half* %p, align 2
   %c = fcmp ugt half %a, 1.0
   %r = select i1 %c, half %a, half 1.0
   store half %r, half* %p
   ret void
 }
 
-; FIXME
-;define void @test_copysign(half* %p, half* %q) {
-;  %a = load half, half* %p, align 2
-;  %b = load half, half* %q, align 2
-;  %r = call half @llvm.copysign.f16(half %a, half %b)
-;  store half %r, half* %p
-;  ret void
-;}
+define void @test_copysign(half* %p, half* %q) {
+; CHECK-LABEL: test_copysign:
+; CHECK:         .pad #4
+; CHECK-NEXT:    sub sp, sp, #4
+; CHECK-NEXT:    vldr.16 s0, [r1]
+; CHECK-NEXT:    vstr.16 s0, [sp]
+; CHECK-NEXT:    vldr.16 s0, [r0]
+; CHECK-NEXT:    ldrb r1, [sp, #1]
+; CHECK-NEXT:    ands r1, r1, #128
+; CHECK-NEXT:    vabs.f16 s0, s0
+; CHECK-NEXT:    movwne r1, #1
+; CHECK-NEXT:    vneg.f16 s2, s0
+; CHECK-NEXT:    cmp r1, #0
+; CHECK-NEXT:    vseleq.f16 s0, s0, s2
+; CHECK-NEXT:    vstr.16 s0, [r0]
+; CHECK-NEXT:    add sp, sp, #4
+; CHECK-NEXT:    bx lr
+  %a = load half, half* %p, align 2
+  %b = load half, half* %q, align 2
+  %r = call half @llvm.copysign.f16(half %a, half %b)
+  store half %r, half* %p
+  ret void
+}
 
 ; FIXME
 ;define void @test_floor(half* %p) {
 ;  %a = load half, half* %p, align 2
 ;  %r = call half @llvm.floor.f16(half %a)
 ;  store half %r, half* %p
 ;  ret void
 ;}