From 0d533433e21621177fb291e2a4901bee11834501 Mon Sep 17 00:00:00 2001
From: Cody Tapscott <topolarity@tapscott.me>
Date: Fri, 7 Oct 2022 10:19:08 -0700
Subject: [PATCH] compiler_rt: Add missing `f16` functions

This change also exposes some of the existing functions under both the
PPC-style names symbols and the compiler-rt-style names, since Zig
currently lowers softfloat calls to the latter.
---
 lib/compiler_rt.zig             | 24 +++++++++++-----
 lib/compiler_rt/addhf3.zig      | 12 ++++++++
 lib/compiler_rt/cmphf2.zig      | 50 +++++++++++++++++++++++++++++++++
 lib/compiler_rt/divhf3.zig      | 11 ++++++++
 lib/compiler_rt/extendhfdf2.zig | 12 ++++++++
 lib/compiler_rt/extendhfsf2.zig |  9 ++----
 lib/compiler_rt/gehf2.zig       | 31 ++++++++++++++++++++
 lib/compiler_rt/mulf3.zig       |  5 ++--
 lib/compiler_rt/mulhf3.zig      | 12 ++++++++
 lib/compiler_rt/neghf2.zig      | 11 ++++++++
 lib/compiler_rt/subhf3.zig      | 12 ++++++++
 lib/compiler_rt/tan.zig         |  6 ++--
 lib/compiler_rt/truncsfhf2.zig  |  9 ++----
 lib/compiler_rt/unordhf2.zig    | 12 ++++++++
 lib/compiler_rt/unordxf2.zig    | 12 ++++++++
 15 files changed, 203 insertions(+), 25 deletions(-)
 create mode 100644 lib/compiler_rt/addhf3.zig
 create mode 100644 lib/compiler_rt/cmphf2.zig
 create mode 100644 lib/compiler_rt/divhf3.zig
 create mode 100644 lib/compiler_rt/extendhfdf2.zig
 create mode 100644 lib/compiler_rt/gehf2.zig
 create mode 100644 lib/compiler_rt/mulhf3.zig
 create mode 100644 lib/compiler_rt/neghf2.zig
 create mode 100644 lib/compiler_rt/subhf3.zig
 create mode 100644 lib/compiler_rt/unordhf2.zig
 create mode 100644 lib/compiler_rt/unordxf2.zig

diff --git a/lib/compiler_rt.zig b/lib/compiler_rt.zig
index d261c49ff1..1597b7e135 100644
--- a/lib/compiler_rt.zig
+++ b/lib/compiler_rt.zig
@@ -4,17 +4,20 @@ comptime {
     _ = @import("compiler_rt/atomics.zig");
 
     _ = @import("compiler_rt/addf3.zig");
+    _ = @import("compiler_rt/addhf3.zig");
     _ = @import("compiler_rt/addsf3.zig");
     _ = @import("compiler_rt/adddf3.zig");
     _ = @import("compiler_rt/addtf3.zig");
     _ = @import("compiler_rt/addxf3.zig");
 
+    _ = @import("compiler_rt/subhf3.zig");
     _ = @import("compiler_rt/subsf3.zig");
     _ = @import("compiler_rt/subdf3.zig");
     _ = @import("compiler_rt/subtf3.zig");
     _ = @import("compiler_rt/subxf3.zig");
 
     _ = @import("compiler_rt/mulf3.zig");
+    _ = @import("compiler_rt/mulhf3.zig");
     _ = @import("compiler_rt/mulsf3.zig");
     _ = @import("compiler_rt/muldf3.zig");
     _ = @import("compiler_rt/multf3.zig");
@@ -34,51 +37,58 @@ comptime {
     _ = @import("compiler_rt/divxc3.zig");
     _ = @import("compiler_rt/divtc3.zig");
 
+    _ = @import("compiler_rt/neghf2.zig");
     _ = @import("compiler_rt/negsf2.zig");
     _ = @import("compiler_rt/negdf2.zig");
     _ = @import("compiler_rt/negtf2.zig");
     _ = @import("compiler_rt/negxf2.zig");
 
     _ = @import("compiler_rt/comparef.zig");
+    _ = @import("compiler_rt/cmphf2.zig");
     _ = @import("compiler_rt/cmpsf2.zig");
     _ = @import("compiler_rt/cmpdf2.zig");
     _ = @import("compiler_rt/cmptf2.zig");
     _ = @import("compiler_rt/cmpxf2.zig");
+    _ = @import("compiler_rt/gehf2.zig");
     _ = @import("compiler_rt/gesf2.zig");
     _ = @import("compiler_rt/gedf2.zig");
-    _ = @import("compiler_rt/getf2.zig");
     _ = @import("compiler_rt/gexf2.zig");
+    _ = @import("compiler_rt/getf2.zig");
+    _ = @import("compiler_rt/unordhf2.zig");
     _ = @import("compiler_rt/unordsf2.zig");
     _ = @import("compiler_rt/unorddf2.zig");
+    _ = @import("compiler_rt/unordxf2.zig");
     _ = @import("compiler_rt/unordtf2.zig");
 
     _ = @import("compiler_rt/extendf.zig");
-    _ = @import("compiler_rt/extenddftf2.zig");
-    _ = @import("compiler_rt/extenddfxf2.zig");
     _ = @import("compiler_rt/extendhfsf2.zig");
+    _ = @import("compiler_rt/extendhfdf2.zig");
     _ = @import("compiler_rt/extendhftf2.zig");
     _ = @import("compiler_rt/extendhfxf2.zig");
     _ = @import("compiler_rt/extendsfdf2.zig");
     _ = @import("compiler_rt/extendsftf2.zig");
     _ = @import("compiler_rt/extendsfxf2.zig");
+    _ = @import("compiler_rt/extenddftf2.zig");
+    _ = @import("compiler_rt/extenddfxf2.zig");
     _ = @import("compiler_rt/extendxftf2.zig");
 
     _ = @import("compiler_rt/truncf.zig");
     _ = @import("compiler_rt/truncsfhf2.zig");
     _ = @import("compiler_rt/truncdfhf2.zig");
     _ = @import("compiler_rt/truncdfsf2.zig");
+    _ = @import("compiler_rt/truncxfhf2.zig");
+    _ = @import("compiler_rt/truncxfsf2.zig");
+    _ = @import("compiler_rt/truncxfdf2.zig");
     _ = @import("compiler_rt/trunctfhf2.zig");
     _ = @import("compiler_rt/trunctfsf2.zig");
     _ = @import("compiler_rt/trunctfdf2.zig");
     _ = @import("compiler_rt/trunctfxf2.zig");
-    _ = @import("compiler_rt/truncxfhf2.zig");
-    _ = @import("compiler_rt/truncxfsf2.zig");
-    _ = @import("compiler_rt/truncxfdf2.zig");
 
-    _ = @import("compiler_rt/divtf3.zig");
+    _ = @import("compiler_rt/divhf3.zig");
     _ = @import("compiler_rt/divsf3.zig");
     _ = @import("compiler_rt/divdf3.zig");
     _ = @import("compiler_rt/divxf3.zig");
+    _ = @import("compiler_rt/divtf3.zig");
     _ = @import("compiler_rt/sin.zig");
     _ = @import("compiler_rt/cos.zig");
     _ = @import("compiler_rt/sincos.zig");
diff --git a/lib/compiler_rt/addhf3.zig b/lib/compiler_rt/addhf3.zig
new file mode 100644
index 0000000000..12086aef38
--- /dev/null
+++ b/lib/compiler_rt/addhf3.zig
@@ -0,0 +1,12 @@
+const common = @import("./common.zig");
+const addf3 = @import("./addf3.zig").addf3;
+
+pub const panic = common.panic;
+
+comptime {
+    @export(__addhf3, .{ .name = "__addhf3", .linkage = common.linkage });
+}
+
+fn __addhf3(a: f16, b: f16) callconv(.C) f16 {
+    return addf3(f16, a, b);
+}
diff --git a/lib/compiler_rt/cmphf2.zig b/lib/compiler_rt/cmphf2.zig
new file mode 100644
index 0000000000..d5ee3f1daa
--- /dev/null
+++ b/lib/compiler_rt/cmphf2.zig
@@ -0,0 +1,50 @@
+///! The quoted behavior definitions are from
+///! https://gcc.gnu.org/onlinedocs/gcc-12.1.0/gccint/Soft-float-library-routines.html#Soft-float-library-routines
+const common = @import("./common.zig");
+const comparef = @import("./comparef.zig");
+
+pub const panic = common.panic;
+
+comptime {
+    @export(__eqhf2, .{ .name = "__eqhf2", .linkage = common.linkage });
+    @export(__nehf2, .{ .name = "__nehf2", .linkage = common.linkage });
+    @export(__lehf2, .{ .name = "__lehf2", .linkage = common.linkage });
+    @export(__cmphf2, .{ .name = "__cmphf2", .linkage = common.linkage });
+    @export(__lthf2, .{ .name = "__lthf2", .linkage = common.linkage });
+}
+
+/// "These functions calculate a <=> b. That is, if a is less than b, they return -1;
+/// if a is greater than b, they return 1; and if a and b are equal they return 0.
+/// If either argument is NaN they return 1..."
+///
+/// Note that this matches the definition of `__lehf2`, `__eqhf2`, `__nehf2`, `__cmphf2`,
+/// and `__lthf2`.
+fn __cmphf2(a: f16, b: f16) callconv(.C) i32 {
+    return @enumToInt(comparef.cmpf2(f16, comparef.LE, a, b));
+}
+
+/// "These functions return a value less than or equal to zero if neither argument is NaN,
+/// and a is less than or equal to b."
+pub fn __lehf2(a: f16, b: f16) callconv(.C) i32 {
+    return __cmphf2(a, b);
+}
+
+/// "These functions return zero if neither argument is NaN, and a and b are equal."
+/// Note that due to some kind of historical accident, __eqhf2 and __nehf2 are defined
+/// to have the same return value.
+pub fn __eqhf2(a: f16, b: f16) callconv(.C) i32 {
+    return __cmphf2(a, b);
+}
+
+/// "These functions return a nonzero value if either argument is NaN, or if a and b are unequal."
+/// Note that due to some kind of historical accident, __eqhf2 and __nehf2 are defined
+/// to have the same return value.
+pub fn __nehf2(a: f16, b: f16) callconv(.C) i32 {
+    return __cmphf2(a, b);
+}
+
+/// "These functions return a value less than zero if neither argument is NaN, and a
+/// is strictly less than b."
+pub fn __lthf2(a: f16, b: f16) callconv(.C) i32 {
+    return __cmphf2(a, b);
+}
diff --git a/lib/compiler_rt/divhf3.zig b/lib/compiler_rt/divhf3.zig
new file mode 100644
index 0000000000..ad73a5ddb2
--- /dev/null
+++ b/lib/compiler_rt/divhf3.zig
@@ -0,0 +1,11 @@
+const common = @import("common.zig");
+const divsf3 = @import("./divsf3.zig");
+
+comptime {
+    @export(__divhf3, .{ .name = "__divhf3", .linkage = common.linkage });
+}
+
+pub fn __divhf3(a: f16, b: f16) callconv(.C) f16 {
+    // TODO: more efficient implementation
+    return @floatCast(f16, divsf3.__divsf3(a, b));
+}
diff --git a/lib/compiler_rt/extendhfdf2.zig b/lib/compiler_rt/extendhfdf2.zig
new file mode 100644
index 0000000000..f7a94f58ef
--- /dev/null
+++ b/lib/compiler_rt/extendhfdf2.zig
@@ -0,0 +1,12 @@
+const common = @import("./common.zig");
+const extendf = @import("./extendf.zig").extendf;
+
+pub const panic = common.panic;
+
+comptime {
+    @export(__extendhfdf2, .{ .name = "__extendhfdf2", .linkage = common.linkage });
+}
+
+pub fn __extendhfdf2(a: common.F16T) callconv(.C) f64 {
+    return extendf(f64, f16, @bitCast(u16, a));
+}
diff --git a/lib/compiler_rt/extendhfsf2.zig b/lib/compiler_rt/extendhfsf2.zig
index a6bf5f5be5..0c204ec188 100644
--- a/lib/compiler_rt/extendhfsf2.zig
+++ b/lib/compiler_rt/extendhfsf2.zig
@@ -5,22 +5,17 @@ pub const panic = common.panic;
 
 comptime {
     if (common.gnu_f16_abi) {
-        @export(__gnu_h2f_ieee, .{ .name = "__gnu_h2f_ieee", .linkage = common.linkage });
+        @export(__extendhfsf2, .{ .name = "__gnu_h2f_ieee", .linkage = common.linkage });
     } else if (common.want_aeabi) {
         @export(__aeabi_h2f, .{ .name = "__aeabi_h2f", .linkage = common.linkage });
-    } else {
-        @export(__extendhfsf2, .{ .name = "__extendhfsf2", .linkage = common.linkage });
     }
+    @export(__extendhfsf2, .{ .name = "__extendhfsf2", .linkage = common.linkage });
 }
 
 pub fn __extendhfsf2(a: common.F16T) callconv(.C) f32 {
     return extendf(f32, f16, @bitCast(u16, a));
 }
 
-fn __gnu_h2f_ieee(a: common.F16T) callconv(.C) f32 {
-    return extendf(f32, f16, @bitCast(u16, a));
-}
-
 fn __aeabi_h2f(a: u16) callconv(.AAPCS) f32 {
     return extendf(f32, f16, @bitCast(u16, a));
 }
diff --git a/lib/compiler_rt/gehf2.zig b/lib/compiler_rt/gehf2.zig
new file mode 100644
index 0000000000..651cbf943f
--- /dev/null
+++ b/lib/compiler_rt/gehf2.zig
@@ -0,0 +1,31 @@
+///! The quoted behavior definitions are from
+///! https://gcc.gnu.org/onlinedocs/gcc-12.1.0/gccint/Soft-float-library-routines.html#Soft-float-library-routines
+const common = @import("./common.zig");
+const comparef = @import("./comparef.zig");
+
+pub const panic = common.panic;
+
+comptime {
+    @export(__gehf2, .{ .name = "__gehf2", .linkage = common.linkage });
+    @export(__gthf2, .{ .name = "__gthf2", .linkage = common.linkage });
+}
+
+/// "These functions return a value greater than or equal to zero if neither
+/// argument is NaN, and a is greater than or equal to b."
+pub fn __gehf2(a: f16, b: f16) callconv(.C) i32 {
+    return @enumToInt(comparef.cmpf2(f16, comparef.GE, a, b));
+}
+
+/// "These functions return a value greater than zero if neither argument is NaN,
+/// and a is strictly greater than b."
+pub fn __gthf2(a: f16, b: f16) callconv(.C) i32 {
+    return __gehf2(a, b);
+}
+
+fn __aeabi_fcmpge(a: f16, b: f16) callconv(.AAPCS) i32 {
+    return @boolToInt(comparef.cmpf2(f16, comparef.GE, a, b) != .Less);
+}
+
+fn __aeabi_fcmpgt(a: f16, b: f16) callconv(.AAPCS) i32 {
+    return @boolToInt(comparef.cmpf2(f16, comparef.LE, a, b) == .Greater);
+}
diff --git a/lib/compiler_rt/mulf3.zig b/lib/compiler_rt/mulf3.zig
index 770721cb80..b02bd81671 100644
--- a/lib/compiler_rt/mulf3.zig
+++ b/lib/compiler_rt/mulf3.zig
@@ -32,8 +32,9 @@ pub inline fn mulf3(comptime T: type, a: T, b: T) T {
     const infRep = @bitCast(Z, math.inf(T));
     const minNormalRep = @bitCast(Z, math.floatMin(T));
 
-    const aExponent = @truncate(u32, (@bitCast(Z, a) >> significandBits) & maxExponent);
-    const bExponent = @truncate(u32, (@bitCast(Z, b) >> significandBits) & maxExponent);
+    const ZExp = if (typeWidth >= 32) u32 else Z;
+    const aExponent = @truncate(ZExp, (@bitCast(Z, a) >> significandBits) & maxExponent);
+    const bExponent = @truncate(ZExp, (@bitCast(Z, b) >> significandBits) & maxExponent);
     const productSign: Z = (@bitCast(Z, a) ^ @bitCast(Z, b)) & signBit;
 
     var aSignificand: ZSignificand = @intCast(ZSignificand, @bitCast(Z, a) & significandMask);
diff --git a/lib/compiler_rt/mulhf3.zig b/lib/compiler_rt/mulhf3.zig
new file mode 100644
index 0000000000..45251548be
--- /dev/null
+++ b/lib/compiler_rt/mulhf3.zig
@@ -0,0 +1,12 @@
+const common = @import("./common.zig");
+const mulf3 = @import("./mulf3.zig").mulf3;
+
+pub const panic = common.panic;
+
+comptime {
+    @export(__mulhf3, .{ .name = "__mulhf3", .linkage = common.linkage });
+}
+
+pub fn __mulhf3(a: f16, b: f16) callconv(.C) f16 {
+    return mulf3(f16, a, b);
+}
diff --git a/lib/compiler_rt/neghf2.zig b/lib/compiler_rt/neghf2.zig
new file mode 100644
index 0000000000..fe55a751d8
--- /dev/null
+++ b/lib/compiler_rt/neghf2.zig
@@ -0,0 +1,11 @@
+const common = @import("./common.zig");
+
+pub const panic = common.panic;
+
+comptime {
+    @export(__neghf2, .{ .name = "__neghf2", .linkage = common.linkage });
+}
+
+fn __neghf2(a: f16) callconv(.C) f16 {
+    return common.fneg(a);
+}
diff --git a/lib/compiler_rt/subhf3.zig b/lib/compiler_rt/subhf3.zig
new file mode 100644
index 0000000000..b14da2d794
--- /dev/null
+++ b/lib/compiler_rt/subhf3.zig
@@ -0,0 +1,12 @@
+const common = @import("./common.zig");
+
+pub const panic = common.panic;
+
+comptime {
+    @export(__subhf3, .{ .name = "__subhf3", .linkage = common.linkage });
+}
+
+fn __subhf3(a: f16, b: f16) callconv(.C) f16 {
+    const neg_b = @bitCast(f16, @bitCast(u16, b) ^ (@as(u16, 1) << 15));
+    return a + neg_b;
+}
diff --git a/lib/compiler_rt/tan.zig b/lib/compiler_rt/tan.zig
index 9c44e4c682..8b8f8287a3 100644
--- a/lib/compiler_rt/tan.zig
+++ b/lib/compiler_rt/tan.zig
@@ -24,8 +24,10 @@ comptime {
     @export(tanf, .{ .name = "tanf", .linkage = common.linkage });
     @export(tan, .{ .name = "tan", .linkage = common.linkage });
     @export(__tanx, .{ .name = "__tanx", .linkage = common.linkage });
-    const tanq_sym_name = if (common.want_ppc_abi) "tanf128" else "tanq";
-    @export(tanq, .{ .name = tanq_sym_name, .linkage = common.linkage });
+    if (common.want_ppc_abi) {
+        @export(tanq, .{ .name = "tanf128", .linkage = common.linkage });
+    }
+    @export(tanq, .{ .name = "tanq", .linkage = common.linkage });
     @export(tanl, .{ .name = "tanl", .linkage = common.linkage });
 }
 
diff --git a/lib/compiler_rt/truncsfhf2.zig b/lib/compiler_rt/truncsfhf2.zig
index 489fb8658d..010e257923 100644
--- a/lib/compiler_rt/truncsfhf2.zig
+++ b/lib/compiler_rt/truncsfhf2.zig
@@ -5,22 +5,17 @@ pub const panic = common.panic;
 
 comptime {
     if (common.gnu_f16_abi) {
-        @export(__gnu_f2h_ieee, .{ .name = "__gnu_f2h_ieee", .linkage = common.linkage });
+        @export(__truncsfhf2, .{ .name = "__gnu_f2h_ieee", .linkage = common.linkage });
     } else if (common.want_aeabi) {
         @export(__aeabi_f2h, .{ .name = "__aeabi_f2h", .linkage = common.linkage });
-    } else {
-        @export(__truncsfhf2, .{ .name = "__truncsfhf2", .linkage = common.linkage });
     }
+    @export(__truncsfhf2, .{ .name = "__truncsfhf2", .linkage = common.linkage });
 }
 
 pub fn __truncsfhf2(a: f32) callconv(.C) common.F16T {
     return @bitCast(common.F16T, truncf(f16, f32, a));
 }
 
-fn __gnu_f2h_ieee(a: f32) callconv(.C) common.F16T {
-    return @bitCast(common.F16T, truncf(f16, f32, a));
-}
-
 fn __aeabi_f2h(a: f32) callconv(.AAPCS) u16 {
     return @bitCast(common.F16T, truncf(f16, f32, a));
 }
diff --git a/lib/compiler_rt/unordhf2.zig b/lib/compiler_rt/unordhf2.zig
new file mode 100644
index 0000000000..0c2aea629a
--- /dev/null
+++ b/lib/compiler_rt/unordhf2.zig
@@ -0,0 +1,12 @@
+const common = @import("./common.zig");
+const comparef = @import("./comparef.zig");
+
+pub const panic = common.panic;
+
+comptime {
+    @export(__unordhf2, .{ .name = "__unordhf2", .linkage = common.linkage });
+}
+
+pub fn __unordhf2(a: f16, b: f16) callconv(.C) i32 {
+    return comparef.unordcmp(f16, a, b);
+}
diff --git a/lib/compiler_rt/unordxf2.zig b/lib/compiler_rt/unordxf2.zig
new file mode 100644
index 0000000000..e456096370
--- /dev/null
+++ b/lib/compiler_rt/unordxf2.zig
@@ -0,0 +1,12 @@
+const common = @import("./common.zig");
+const comparef = @import("./comparef.zig");
+
+pub const panic = common.panic;
+
+comptime {
+    @export(__unordxf2, .{ .name = "__unordxf2", .linkage = common.linkage });
+}
+
+pub fn __unordxf2(a: f80, b: f80) callconv(.C) i32 {
+    return comparef.unordcmp(f80, a, b);
+}