saturating arithmetic builtins: add, sub, mul, shl (#9619)

- adds 1 simple behavior tests for each
  which does integer and vector ops at
  runtime and comptime
- adds bigint_*_sat() methods for each

- use CreateIntrinsic() which accepts a
  variable number of arguments to pass
  the scale parameter

* update langref
- added case to test/compile_errors.zig given floats

- explain upstream bug in llvm.smul.fix.sat and link to #9643 in langref and commented out test cases

* sat-arithmetic: skip mul tests if arch == .wasm32 because ci is erroring with 'LLVM ERROR: Unable to expand fixed point multiplication' when compiling for wasm32

1 files changed, 32 insertions, 0 deletions

diff --git a/src/BuiltinFn.zig b/src/BuiltinFn.zig
index 8f23ec86d7..e415d27a3a 100644
--- a/src/BuiltinFn.zig
+++ b/src/BuiltinFn.zig
@@ -2,6 +2,7 @@ const std = @import("std");
 
 pub const Tag = enum {
     add_with_overflow,
+    add_with_saturation,
     align_cast,
     align_of,
     as,
@@ -65,6 +66,7 @@ pub const Tag = enum {
     wasm_memory_grow,
     mod,
     mul_with_overflow,
+    mul_with_saturation,
     panic,
     pop_count,
     ptr_cast,
@@ -79,10 +81,12 @@ pub const Tag = enum {
     set_runtime_safety,
     shl_exact,
     shl_with_overflow,
+    shl_with_saturation,
     shr_exact,
     shuffle,
     size_of,
     splat,
+    sub_with_saturation,
     reduce,
     src,
     sqrt,
@@ -528,6 +532,34 @@ pub const list = list: {
             },
         },
         .{
+            "@addWithSaturation",
+            .{
+                .tag = .add_with_saturation,
+                .param_count = 2,
+            },
+        },
+        .{
+            "@subWithSaturation",
+            .{
+                .tag = .sub_with_saturation,
+                .param_count = 2,
+            },
+        },
+        .{
+            "@mulWithSaturation",
+            .{
+                .tag = .mul_with_saturation,
+                .param_count = 2,
+            },
+        },
+        .{
+            "@shlWithSaturation",
+            .{
+                .tag = .shl_with_saturation,
+                .param_count = 2,
+            },
+        },
+        .{
             "@memcpy",
             .{
                 .tag = .memcpy,