fix various fma issues (#533)

This makes `src/builtins.jl` in sync with `bin/generate_builtins.jl`
again. A lot of this code was also out-of-date, now that we only support
1.6, so this includes some cleanup.

Author: KristofferC

bin/generate_builtins.jl

@@ -268,6 +268,32 @@ function maybe_evaluate_builtin(frame, call_expr, expand::Bool)
 """
     if isa(f, Core.IntrinsicFunction)
         cargs = getargs(args, frame)
+        @static if isdefined(Core.Intrinsics, :have_fma)
+            if f === Core.Intrinsics.have_fma && length(cargs) == 1
+                cargs1 = cargs[1]
+                if cargs1 == Float64
+                    return Some{Any}(FMA_FLOAT64[])
+                elseif cargs1 == Float32
+                    return Some{Any}(FMA_FLOAT32[])
+                elseif cargs1 == Float16
+                    return Some{Any}(FMA_FLOAT16[])
+                end
+            end
+        end
+        if f === Core.Intrinsics.muladd_float && length(cargs) == 3
+            a, b, c = cargs
+            Ta, Tb, Tc = typeof(a), typeof(b), typeof(c)
+            if !(Ta == Tb == Tc)
+                error("muladd_float: types of a, b, and c must match")
+            end
+            if Ta == Float64 && FMA_FLOAT64[]
+                f = Core.Intrinsics.fma_float
+            elseif Ta == Float32 && FMA_FLOAT32[]
+                f = Core.Intrinsics.fma_float
+            elseif Ta == Float16 && FMA_FLOAT16[]
+                f = Core.Intrinsics.fma_float
+            end
+        end
         return Some{Any}(ccall(:jl_f_intrinsic_call, Any, (Any, Ptr{Any}, UInt32), f, cargs, length(cargs)))
 """)
     print(io,

src/builtins.jl

@@ -297,6 +297,32 @@ function maybe_evaluate_builtin(frame, call_expr, expand::Bool)
     end
     if isa(f, Core.IntrinsicFunction)
         cargs = getargs(args, frame)
+        @static if isdefined(Core.Intrinsics, :have_fma)
+            if f === Core.Intrinsics.have_fma && length(cargs) == 1
+                cargs1 = cargs[1]
+                if cargs1 == Float64
+                    return Some{Any}(FMA_FLOAT64[])
+                elseif cargs1 == Float32
+                    return Some{Any}(FMA_FLOAT32[])
+                elseif cargs1 == Float16
+                    return Some{Any}(FMA_FLOAT16[])
+                end
+            end
+        end
+        if f === Core.Intrinsics.muladd_float && length(cargs) == 3
+            a, b, c = cargs
+            Ta, Tb, Tc = typeof(a), typeof(b), typeof(c)
+            if !(Ta == Tb == Tc)
+                error("muladd_float: types of a, b, and c must match")
+            end
+            if Ta == Float64 && FMA_FLOAT64[]
+                f = Core.Intrinsics.fma_float
+            elseif Ta == Float32 && FMA_FLOAT32[]
+                f = Core.Intrinsics.fma_float
+            elseif Ta == Float16 && FMA_FLOAT16[]
+                f = Core.Intrinsics.fma_float
+            end
+        end
         return Some{Any}(ccall(:jl_f_intrinsic_call, Any, (Any, Ptr{Any}, UInt32), f, cargs, length(cargs)))
     end
     if isa(f, typeof(kwinvoke))

src/packagedef.jl

@@ -116,6 +116,12 @@ function set_compiled_methods()
     push!(compiled_modules, Base.Threads)
 end
 
+_have_fma_compiled(::Type{T}) where {T} = Core.Intrinsics.have_fma(T)
+
+const FMA_FLOAT64 = Ref(false)
+const FMA_FLOAT32 = Ref(false)
+const FMA_FLOAT16 = Ref(false)
+
 function __init__()
     set_compiled_methods()
     COVERAGE[] = Base.JLOptions().code_coverage
@@ -144,6 +150,12 @@ function __init__()
     #     compiled_calls[(qsym, RT, Core.svec(AT...), Core.Compiler)] = f
     #     precompile(f, AT)
     # end
+    
+    @static if isdefined(Base, :have_fma)
+        FMA_FLOAT64[] = _have_fma_compiled(Float64)
+        FMA_FLOAT32[] = _have_fma_compiled(Float32)
+        FMA_FLOAT16[] = _have_fma_compiled(Float16)
+    end
 end
 
 include("precompile.jl")

test/interpret.jl

@@ -895,3 +895,14 @@ end
     iscallexpr(ex::Expr) = ex.head === :call
     @test (@interpret iscallexpr(:(sin(3.14))))
 end
+
+if isdefined(Base, :have_fma)
+f_fma() = Base.have_fma(Float64)
+@testset "fma" begin
+    @test (@interpret f_fma()) == f_fma()
+    a, b, c = (1.0585073227945125, -0.00040303348596386557, 1.5051263504758005e-16)
+    @test (@interpret muladd(a, b, c)) === muladd(a,b,c)
+    a = 1.0883740903666346; b = 2/3
+    @test (@interpret a^b) === a^b
+end
+end