From 7b978bf1e05727f15fc83ae7d2455c08833cc439 Mon Sep 17 00:00:00 2001
From: Cody Tapscott <topolarity@tapscott.me>
Date: Wed, 5 Oct 2022 05:34:52 -0700
Subject: stage2: Rename `Value.compare` to `compareAll`, etc.

These functions have a very error-prone API. They are essentially
`all(cmp(op, ...))` but that's not reflected in the name.

This renames these functions to `compareAllAgainstZero...` etc.
for clarity and fixes >20 locations where the predicate was
incorrect.

In the future, the scalar `compare` should probably be split off
from the vector comparison. Rank-polymorphic programming is great,
but a proper implementation in Zig would decouple comparison and
reduction, which then needs a way to fuse ops at comptime.
---
 src/value.zig | 20 +++++++++++---------
 1 file changed, 11 insertions(+), 9 deletions(-)

(limited to 'src/value.zig')

diff --git a/src/value.zig b/src/value.zig
index 792ec5068f..6b5ffe02ab 100644
--- a/src/value.zig
+++ b/src/value.zig
@@ -2005,8 +2005,8 @@ pub const Value = extern union {
     }
 
     /// Asserts the values are comparable. Both operands have type `ty`.
-    /// Vector results will be reduced with AND.
-    pub fn compare(lhs: Value, op: std.math.CompareOperator, rhs: Value, ty: Type, mod: *Module) bool {
+    /// For vectors, returns true if comparison is true for ALL elements.
+    pub fn compareAll(lhs: Value, op: std.math.CompareOperator, rhs: Value, ty: Type, mod: *Module) bool {
         if (ty.zigTypeTag() == .Vector) {
             var i: usize = 0;
             while (i < ty.vectorLen()) : (i += 1) {
@@ -2035,21 +2035,23 @@ pub const Value = extern union {
     }
 
     /// Asserts the value is comparable.
-    /// Vector results will be reduced with AND.
-    pub fn compareWithZero(lhs: Value, op: std.math.CompareOperator) bool {
-        return compareWithZeroAdvanced(lhs, op, null) catch unreachable;
+    /// For vectors, returns true if comparison is true for ALL elements.
+    ///
+    /// Note that `!compareAllWithZero(.eq, ...) != compareAllWithZero(.neq, ...)`
+    pub fn compareAllWithZero(lhs: Value, op: std.math.CompareOperator) bool {
+        return compareAllWithZeroAdvanced(lhs, op, null) catch unreachable;
     }
 
-    pub fn compareWithZeroAdvanced(
+    pub fn compareAllWithZeroAdvanced(
         lhs: Value,
         op: std.math.CompareOperator,
         sema_kit: ?Module.WipAnalysis,
     ) Module.CompileError!bool {
         switch (lhs.tag()) {
-            .repeated => return lhs.castTag(.repeated).?.data.compareWithZeroAdvanced(op, sema_kit),
+            .repeated => return lhs.castTag(.repeated).?.data.compareAllWithZeroAdvanced(op, sema_kit),
             .aggregate => {
                 for (lhs.castTag(.aggregate).?.data) |elem_val| {
-                    if (!(try elem_val.compareWithZeroAdvanced(op, sema_kit))) return false;
+                    if (!(try elem_val.compareAllWithZeroAdvanced(op, sema_kit))) return false;
                 }
                 return true;
             },
@@ -2982,7 +2984,7 @@ pub const Value = extern union {
             .int_i64,
             .int_big_positive,
             .int_big_negative,
-            => compareWithZero(self, .eq),
+            => compareAllWithZero(self, .eq),
 
             .undef => unreachable,
             .unreachable_value => unreachable,
-- 
cgit v1.2.3