bit shifting safety

 * add u3, u4, u5, u6, u7 and i3, i4, i5, i6, i7
 * shift operations shift amount parameter type is
   integer with log2 bit width of other param
   - This enforces not violating undefined behavior on
     shift amount >= bit width with the type system
 * clean up math.log, math.ln, math.log2, math.log10

closes #403

1 files changed, 14 insertions, 0 deletions

diff --git a/test/compile_errors.zig b/test/compile_errors.zig
index 358569d0ef..16c36dc294 100644
--- a/test/compile_errors.zig
+++ b/test/compile_errors.zig
@@ -1973,4 +1973,18 @@ pub fn addCases(cases: &tests.CompileErrorContext) {
         \\}
     ,
         ".tmp_source.zig:2:15: error: exact shift shifted out 1 bits");
+
+    cases.add("shifting without int type or comptime known",
+        \\export fn entry(x: u8) -> u8 {
+        \\    return 0x11 << x;
+        \\}
+    ,
+        ".tmp_source.zig:2:17: error: LHS of shift must be an integer type, or RHS must be compile-time known");
+
+    cases.add("shifting RHS is log2 of LHS int bit width",
+        \\export fn entry(x: u8, y: u8) -> u8 {
+        \\    return x << y;
+        \\}
+    ,
+        ".tmp_source.zig:2:17: error: expected type 'u3', found 'u8'");
 }