[WebAssembly] Implement all f16x8 unary instructions.

[brendandahl]

All of these instructions can be generated using regular LL intrinsics.

Specified at:
https://github.com/WebAssembly/half-precision/blob/29a9b9462c9285d4ccc1a5dc39214ddfd1892658/proposals/half-precision/Overview.md

[llvmbot]

@llvm/pr-subscribers-backend-webassembly

@llvm/pr-subscribers-mc

Author: Brendan Dahl (brendandahl)

Changes

All of these instructions can be generated using regular LL intrinsics.

Specified at:
https://github.com/WebAssembly/half-precision/blob/29a9b9462c9285d4ccc1a5dc39214ddfd1892658/proposals/half-precision/Overview.md

---

Full diff: https://github.com/llvm/llvm-project/pull/94063.diff

3 Files Affected:

• (modified) llvm/lib/Target/WebAssembly/WebAssemblyInstrSIMD.td (+18-2)
• (modified) llvm/test/CodeGen/WebAssembly/half-precision.ll (+89)
• (modified) llvm/test/MC/WebAssembly/simd-encodings.s (+21)

diff --git a/llvm/lib/Target/WebAssembly/WebAssemblyInstrSIMD.td b/llvm/lib/Target/WebAssembly/WebAssemblyInstrSIMD.td
index b800123ac0fff..3c97befcea1a4 100644
--- a/llvm/lib/Target/WebAssembly/WebAssemblyInstrSIMD.td
+++ b/llvm/lib/Target/WebAssembly/WebAssemblyInstrSIMD.td
@@ -828,12 +828,18 @@ multiclass SIMDBitwise<SDPatternOperator node, string name, bits<32> simdop,
             (!cast<NI>(NAME) $lhs, $rhs)>;
 }
 
-multiclass SIMDUnary<Vec vec, SDPatternOperator node, string name, bits<32> simdop> {
+multiclass SIMDUnary<Vec vec, SDPatternOperator node, string name,
+                     bits<32> simdop, list<Predicate> reqs = []> {
   defm _#vec : SIMD_I<(outs V128:$dst), (ins V128:$v), (outs), (ins),
                       [(set (vec.vt V128:$dst),
                         (vec.vt (node (vec.vt V128:$v))))],
                       vec.prefix#"."#name#"\t$dst, $v",
-                      vec.prefix#"."#name, simdop>;
+                      vec.prefix#"."#name, simdop, reqs>;
+}
+
+multiclass HalfPrecisionUnary<Vec vec, SDPatternOperator node, string name,
+                              bits<32> simdop> {
+  defm "" : SIMDUnary<vec, node, name, simdop, [HasHalfPrecision]>;
 }
 
 // Bitwise logic: v128.not
@@ -1190,6 +1196,10 @@ defm EXTMUL_HIGH_U :
 multiclass SIMDUnaryFP<SDNode node, string name, bits<32> baseInst> {
   defm "" : SIMDUnary<F32x4, node, name, baseInst>;
   defm "" : SIMDUnary<F64x2, node, name, !add(baseInst, 12)>;
+  // Unlike F32x4 and F64x2 there's not a gap in the opcodes between "neg" and
+  // "sqrt" so subtract one from the offset.
+  defm "" : HalfPrecisionUnary<F16x8, node, name,
+                               !add(baseInst,!if(!eq(name, "sqrt"), 80, 81))>;
 }
 
 // Absolute value: abs
@@ -1210,14 +1220,20 @@ defm CEIL : SIMDUnary<F64x2, fceil, "ceil", 0x74>;
 defm FLOOR : SIMDUnary<F64x2, ffloor, "floor", 0x75>;
 defm TRUNC: SIMDUnary<F64x2, ftrunc, "trunc", 0x7a>;
 defm NEAREST: SIMDUnary<F64x2, fnearbyint, "nearest", 0x94>;
+defm CEIL : HalfPrecisionUnary<F16x8, fceil, "ceil", 0x13c>;
+defm FLOOR : HalfPrecisionUnary<F16x8, ffloor, "floor", 0x13d>;
+defm TRUNC : HalfPrecisionUnary<F16x8, ftrunc, "trunc", 0x13e>;
+defm NEAREST : HalfPrecisionUnary<F16x8, fnearbyint, "nearest", 0x13f>;
 
 // WebAssembly doesn't expose inexact exceptions, so map frint to fnearbyint.
 def : Pat<(v4f32 (frint (v4f32 V128:$src))), (NEAREST_F32x4 V128:$src)>;
 def : Pat<(v2f64 (frint (v2f64 V128:$src))), (NEAREST_F64x2 V128:$src)>;
+def : Pat<(v8f16 (frint (v8f16 V128:$src))), (NEAREST_F16x8 V128:$src)>;
 
 // WebAssembly always rounds ties-to-even, so map froundeven to fnearbyint.
 def : Pat<(v4f32 (froundeven (v4f32 V128:$src))), (NEAREST_F32x4 V128:$src)>;
 def : Pat<(v2f64 (froundeven (v2f64 V128:$src))), (NEAREST_F64x2 V128:$src)>;
+def : Pat<(v8f16 (froundeven (v8f16 V128:$src))), (NEAREST_F16x8 V128:$src)>;
 
 //===----------------------------------------------------------------------===//
 // Floating-point binary arithmetic
diff --git a/llvm/test/CodeGen/WebAssembly/half-precision.ll b/llvm/test/CodeGen/WebAssembly/half-precision.ll
index cca25b485cdf2..0f0a159091514 100644
--- a/llvm/test/CodeGen/WebAssembly/half-precision.ll
+++ b/llvm/test/CodeGen/WebAssembly/half-precision.ll
@@ -157,3 +157,92 @@ define <8 x i1> @compare_oge_v8f16 (<8 x half> %x, <8 x half> %y) {
   %res = fcmp oge <8 x half> %x, %y
   ret <8 x i1> %res
 }
+
+; CHECK-LABEL: abs_v8f16:
+; CHECK-NEXT:  .functype abs_v8f16 (v128) -> (v128)
+; CHECK-NEXT:  f16x8.abs $push0=, $0
+; CHECK-NEXT:  return $pop0
+declare <8 x half> @llvm.fabs.v8f16(<8 x half>) nounwind readnone
+define <8 x half> @abs_v8f16(<8 x half> %x) {
+  %a = call <8 x half> @llvm.fabs.v8f16(<8 x half> %x)
+  ret <8 x half> %a
+}
+
+; CHECK-LABEL: neg_v8f16:
+; CHECK-NEXT:  .functype neg_v8f16 (v128) -> (v128)
+; CHECK-NEXT:  f16x8.neg $push0=, $0
+; CHECK-NEXT:  return $pop0
+define <8 x half> @neg_v8f16(<8 x half> %x) {
+  %a = fsub nsz <8 x half> <half 0., half 0., half 0., half 0., half 0., half 0., half 0., half 0.>, %x
+  ret <8 x half> %a
+}
+
+; CHECK-LABEL: sqrt_v8f16:
+; CHECK-NEXT:  .functype sqrt_v8f16 (v128) -> (v128)
+; CHECK-NEXT:  f16x8.sqrt $push0=, $0
+; CHECK-NEXT:  return $pop0
+declare <8 x half> @llvm.sqrt.v8f16(<8 x half> %x)
+define <8 x half> @sqrt_v8f16(<8 x half> %x) {
+  %a = call <8 x half> @llvm.sqrt.v8f16(<8 x half> %x)
+  ret <8 x half> %a
+}
+
+; CHECK-LABEL: ceil_v8f16:
+; CHECK-NEXT:  .functype ceil_v8f16 (v128) -> (v128){{$}}
+; CHECK-NEXT:  f16x8.ceil $push[[R:[0-9]+]]=, $0{{$}}
+; CHECK-NEXT:  return $pop[[R]]{{$}}
+declare <8 x half> @llvm.ceil.v8f16(<8 x half>)
+define <8 x half> @ceil_v8f16(<8 x half> %a) {
+  %v = call <8 x half> @llvm.ceil.v8f16(<8 x half> %a)
+  ret <8 x half> %v
+}
+
+; CHECK-LABEL: floor_v8f16:
+; CHECK-NEXT:  .functype floor_v8f16 (v128) -> (v128){{$}}
+; CHECK-NEXT:  f16x8.floor $push[[R:[0-9]+]]=, $0{{$}}
+; CHECK-NEXT:  return $pop[[R]]{{$}}
+declare <8 x half> @llvm.floor.v8f16(<8 x half>)
+define <8 x half> @floor_v8f16(<8 x half> %a) {
+  %v = call <8 x half> @llvm.floor.v8f16(<8 x half> %a)
+  ret <8 x half> %v
+}
+
+; CHECK-LABEL: trunc_v8f16:
+; CHECK-NEXT:  .functype trunc_v8f16 (v128) -> (v128){{$}}
+; CHECK-NEXT:  f16x8.trunc $push[[R:[0-9]+]]=, $0{{$}}
+; CHECK-NEXT:  return $pop[[R]]{{$}}
+declare <8 x half> @llvm.trunc.v8f16(<8 x half>)
+define <8 x half> @trunc_v8f16(<8 x half> %a) {
+  %v = call <8 x half> @llvm.trunc.v8f16(<8 x half> %a)
+  ret <8 x half> %v
+}
+
+; CHECK-LABEL: nearest_v8f16:
+; CHECK-NEXT:  .functype nearest_v8f16 (v128) -> (v128){{$}}
+; CHECK-NEXT:  f16x8.nearest $push[[R:[0-9]+]]=, $0{{$}}
+; CHECK-NEXT:  return $pop[[R]]{{$}}
+declare <8 x half> @llvm.nearbyint.v8f16(<8 x half>)
+define <8 x half> @nearest_v8f16(<8 x half> %a) {
+  %v = call <8 x half> @llvm.nearbyint.v8f16(<8 x half> %a)
+  ret <8 x half> %v
+}
+
+; CHECK-LABEL: nearest_v8f16_via_rint:
+; CHECK-NEXT:  .functype nearest_v8f16_via_rint (v128) -> (v128){{$}}
+; CHECK-NEXT:  f16x8.nearest $push[[R:[0-9]+]]=, $0{{$}}
+; CHECK-NEXT:  return $pop[[R]]{{$}}
+declare <8 x half> @llvm.rint.v8f16(<8 x half>)
+define <8 x half> @nearest_v8f16_via_rint(<8 x half> %a) {
+  %v = call <8 x half> @llvm.rint.v8f16(<8 x half> %a)
+  ret <8 x half> %v
+}
+
+; CHECK-LABEL: nearest_v8f16_via_roundeven:
+; CHECK-NEXT:  .functype nearest_v8f16_via_roundeven (v128) -> (v128){{$}}
+; CHECK-NEXT:  f16x8.nearest $push[[R:[0-9]+]]=, $0{{$}}
+; CHECK-NEXT:  return $pop[[R]]{{$}}
+declare <8 x half> @llvm.roundeven.v8f16(<8 x half>)
+define <8 x half> @nearest_v8f16_via_roundeven(<8 x half> %a) {
+  %v = call <8 x half> @llvm.roundeven.v8f16(<8 x half> %a)
+  ret <8 x half> %v
+}
diff --git a/llvm/test/MC/WebAssembly/simd-encodings.s b/llvm/test/MC/WebAssembly/simd-encodings.s
index aa70815245e5d..8e4d9301b6026 100644
--- a/llvm/test/MC/WebAssembly/simd-encodings.s
+++ b/llvm/test/MC/WebAssembly/simd-encodings.s
@@ -893,4 +893,25 @@ main:
     # CHECK: f16x8.ge # encoding: [0xfd,0xc5,0x02]
     f16x8.ge
 
+    # CHECK: f16x8.abs # encoding: [0xfd,0xb1,0x02]
+    f16x8.abs
+
+    # CHECK: f16x8.neg # encoding: [0xfd,0xb2,0x02]
+    f16x8.neg
+
+    # CHECK: f16x8.sqrt # encoding: [0xfd,0xb3,0x02]
+    f16x8.sqrt
+
+    # CHECK: f16x8.ceil # encoding: [0xfd,0xbc,0x02]
+    f16x8.ceil
+
+    # CHECK: f16x8.floor # encoding: [0xfd,0xbd,0x02]
+    f16x8.floor
+
+    # CHECK: f16x8.trunc # encoding: [0xfd,0xbe,0x02]
+    f16x8.trunc
+
+    # CHECK: f16x8.nearest # encoding: [0xfd,0xbf,0x02]
+    f16x8.nearest
+
     end_function