Replace memory.op.cmp with optimized equal version

Deprecate cmp.
Fix #68.

5 files changed, 104 insertions, 90 deletions

diff --git a/arch/build.ninja b/arch/build.ninja
index 824efa4..cf05696 100644
--- a/arch/build.ninja
+++ b/arch/build.ninja
@@ -6,9 +6,9 @@ rule archive
 
 build abs.o: gas x64/linux/math/abs.S
 build log.o: gas x64/linux/math/log.S
-build cmp.o: gas x64/linux/memory/cmp.S
+build equal.o: gas x64/linux/memory/equal.S
 build fill.o: gas x64/linux/memory/fill.S
 build copy.o: gas x64/linux/memory/copy.S
 build syscall.o: gas x64/linux/syscall.S
 
-build tanya.a: archive syscall.o copy.o fill.o cmp.o log.o abs.o
+build tanya.a: archive syscall.o copy.o fill.o equal.o log.o abs.o
diff --git a/arch/x64/linux/memory/cmp.S b/arch/x64/linux/memory/equal.S
index bd9f02e..37a906a 100644
--- a/arch/x64/linux/memory/cmp.S
+++ b/arch/x64/linux/memory/equal.S
@@ -1,20 +1,19 @@
 	.text
 
 /*
- * cmpMemory.
+ * equalMemory.
  *
  * rdi - r1 length
  * rsi - r1 data.
  * rdx - r2 length.
  * rcx - r2 data.
  */
-	.globl _D5tanya6memory2op9cmpMemoryFNaNbNixAvxQdZi
-	.type _D5tanya6memory2op9cmpMemoryFNaNbNixAvxQdZi, @function
-_D5tanya6memory2op9cmpMemoryFNaNbNixAvxQdZi:
+	.globl _D5tanya6memory2op11equalMemoryFNaNbNixAvxQdZb
+	.type _D5tanya6memory2op11equalMemoryFNaNbNixAvxQdZb, @function
+_D5tanya6memory2op11equalMemoryFNaNbNixAvxQdZb:
 		// Compare the lengths
 		cmp %rdx, %rdi
-		jl  less
-		jg  greater
+		jne not_equal
 
 		mov %rcx, %rdi
 
@@ -26,8 +25,7 @@ _D5tanya6memory2op9cmpMemoryFNaNbNixAvxQdZi:
 
 	naligned:
 		cmpsb
-		jl less
-		jg greater
+		jne not_equal
 
 		dec %rdx
 		test $0x07, %edi
@@ -38,8 +36,7 @@ _D5tanya6memory2op9cmpMemoryFNaNbNixAvxQdZi:
 		shr $0x03, %rcx
 
 		repe cmpsq
-		jl less
-		jg greater
+		jne not_equal
 
 		and $0x07, %edx
 		jz equal
@@ -49,19 +46,14 @@ _D5tanya6memory2op9cmpMemoryFNaNbNixAvxQdZi:
 		cmp $0x0, %rcx
 
 		repe cmpsb
-		jl less
-		jg greater
+		jne not_equal
 
 	equal:
-		xor %rax, %rax // Return 0
-		jmp end
-
-	greater:
-		mov $0x01, %rax
+		mov $0x01, %rax // Return 1
 		jmp end
 
-	less:
-		mov $-0x01, %rax
+	not_equal:
+		xor %rax, %rax // Return 0
 
 	end:
 		ret
diff --git a/source/tanya/algorithm/comparison.d b/source/tanya/algorithm/comparison.d
index 88f6860..904f045 100644
--- a/source/tanya/algorithm/comparison.d
+++ b/source/tanya/algorithm/comparison.d
@@ -15,8 +15,8 @@
 module tanya.algorithm.comparison;
 
 import tanya.algorithm.mutation;
-import tanya.math : isNaN;
-import tanya.memory.op;
+import tanya.math;
+static import tanya.memory.op;
 import tanya.meta.metafunction;
 import tanya.meta.trait;
 import tanya.meta.transform;
@@ -296,7 +296,7 @@ if (allSatisfy!(isInputRange, R1, R2)
             && is(R1 == R2)
             && __traits(isPOD, ElementType!R1))
     {
-        return cmp(r1, r2) == 0;
+        return tanya.memory.op.equal(r1, r2);
     }
     else
     {
diff --git a/source/tanya/format.d b/source/tanya/format.d
index 2a30822..fa46945 100644
--- a/source/tanya/format.d
+++ b/source/tanya/format.d
@@ -43,7 +43,7 @@ import tanya.algorithm.comparison;
 import tanya.container.string;
 import tanya.encoding.ascii;
 import tanya.math;
-import tanya.memory.op;
+static import tanya.memory.op;
 import tanya.meta.metafunction;
 import tanya.meta.trait;
 import tanya.meta.transform;
@@ -1351,7 +1351,7 @@ do
         intSlice.popBack();
     }
     const begin = buffer.length - intSlice.length;
-    copy(intSlice, buffer[begin .. $]);
+    tanya.memory.op.copy(intSlice, buffer[begin .. $]);
 
     exponent = cast(int) (intSlice.length + mismatch);
 
@@ -1388,7 +1388,7 @@ do
 
     char[21] intBuffer;
     auto intSlice = integral2String(decimal, intBuffer);
-    copy(intSlice, buffer);
+    tanya.memory.op.copy(intSlice, buffer);
     exponent = cast(int) intSlice.length;
 
     size_t position = exponent;
@@ -1903,7 +1903,7 @@ private char[] errol3(double value,
         if (pathologies[middle].representation == bits.integral)
         {
             exponent = pathologies[middle].exponent;
-            copy(pathologies[middle].digits, buffer);
+            tanya.memory.op.copy(pathologies[middle].digits, buffer);
             return buffer[0 .. pathologies[middle].digits.length];
         }
         else if (pathologies[middle].representation < bits.integral)
@@ -2054,7 +2054,7 @@ if (isFloatingPoint!T)
         {
             length = precision + 1;
         }
-        realString[1 .. length].copy(bufferSlice);
+        tanya.memory.op.copy(realString[1 .. length], bufferSlice);
         bufferSlice.popFrontExactly(length - 1);
 
         // Dump the exponent.
@@ -2116,7 +2116,7 @@ if (isFloatingPoint!T)
                 n = precision;
             }
 
-            fill!'0'(bufferSlice[0 .. n]);
+            tanya.memory.op.fill!'0'(bufferSlice[0 .. n]);
             bufferSlice.popFrontExactly(n);
 
             if ((length + n) > precision)
@@ -2124,7 +2124,7 @@ if (isFloatingPoint!T)
                 length = precision - n;
             }
 
-            realString[0 .. length].copy(bufferSlice);
+            tanya.memory.op.copy(realString[0 .. length], bufferSlice);
             bufferSlice.popFrontExactly(length);
         }
         else if (cast(uint) decimalPoint >= length)
@@ -2142,7 +2142,7 @@ if (isFloatingPoint!T)
             {
                 n = decimalPoint - n;
 
-                fill!'0'(bufferSlice[0 .. n]);
+                tanya.memory.op.fill!'0'(bufferSlice[0 .. n]);
                 bufferSlice.popFrontExactly(n);
             }
             if (precision != 0)
@@ -2173,7 +2173,7 @@ if (isFloatingPoint!T)
                 length = precision + decimalPoint;
             }
 
-            realString[n .. length].copy(bufferSlice);
+            tanya.memory.op.copy(realString[n .. length], bufferSlice);
             bufferSlice.popFrontExactly(length - n);
         }
     }
diff --git a/source/tanya/memory/op.d b/source/tanya/memory/op.d
index 8e56c80..b411ed7 100644
--- a/source/tanya/memory/op.d
+++ b/source/tanya/memory/op.d
@@ -24,7 +24,7 @@ version (TanyaNative)
     extern private void moveMemory(const void[], void[])
     pure nothrow @system @nogc;
 
-    extern private int cmpMemory(const void[], const void[])
+    extern private bool equalMemory(const void[], const void[])
     pure nothrow @system @nogc;
 }
 else
@@ -43,7 +43,7 @@ version (TanyaNative)
 
     @nogc nothrow pure @safe unittest
     {
-        assert(cmp(null, null) == 0);
+        assert(equal(null, null));
     }
 }
 
@@ -91,7 +91,7 @@ do
     ubyte[9] source = [1, 2, 3, 4, 5, 6, 7, 8, 9];
     ubyte[9] target;
     source.copy(target);
-    assert(cmp(source, target) == 0);
+    assert(equal(source, target));
 }
 
 @nogc nothrow pure @safe unittest
@@ -110,7 +110,7 @@ do
         ubyte[8] source = [1, 2, 3, 4, 5, 6, 7, 8];
         ubyte[8] target;
         source.copy(target);
-        assert(cmp(source, target) == 0);
+        assert(equal(source, target));
     }
 }
 
@@ -212,7 +212,7 @@ do
     ubyte[6] expected = [ 'a', 'a', 'a', 'a', 'b', 'b' ];
 
     copyBackward(mem[0 .. 4], mem[2 .. $]);
-    assert(cmp(expected, mem) == 0);
+    assert(equal(expected, mem));
 }
 
 @nogc nothrow pure @safe unittest
@@ -221,7 +221,7 @@ do
     ubyte[9] r2;
 
     copyBackward(r1, r2);
-    assert(cmp(r1, r2) == 0);
+    assert(equal(r1, r2));
 }
 
 /**
@@ -241,6 +241,7 @@ do
  *          negative integer if $(D_INLINECODE r2 > r1),
  *          `0` if $(D_INLINECODE r1 == r2).
  */
+deprecated("Use tanya.memory.op.equal() or tanya.algorithm.comparison.compare() instead")
 int cmp(const void[] r1, const void[] r2) @nogc nothrow pure @trusted
 in
 {
@@ -249,48 +250,13 @@ in
 }
 do
 {
-    version (TanyaNative)
+    import core.stdc.string : memcmp;
+
+    if (r1.length > r2.length)
     {
-        return cmpMemory(r1, r2);
-    }
-    else
-    {
-        if (r1.length > r2.length)
-        {
-            return 1;
-        }
-        return r1.length < r2.length ? -1 : memcmp(r1.ptr, r2.ptr, r1.length);
+        return 1;
     }
-}
-
-///
-@nogc nothrow pure @safe unittest
-{
-    ubyte[4] r1 = [ 'a', 'b', 'c', 'd' ];
-    ubyte[3] r2 = [ 'c', 'a', 'b' ];
-
-    assert(cmp(r1[0 .. 3], r2[]) < 0);
-    assert(cmp(r2[], r1[0 .. 3]) > 0);
-
-    assert(cmp(r1, r2) > 0);
-    assert(cmp(r2, r1) < 0);
-}
-
-@nogc nothrow pure @safe unittest
-{
-    ubyte[16] r1 = [
-        'a', 'b', 'c', 'd', 'e', 'f', 'g', 'h',
-        'i', 'j', 'k', 'l', 'm', 'n', 'o', 'p',
-    ];
-    ubyte[16] r2 = [
-        'a', 'b', 'c', 'd', 'e', 'f', 'g', 'h',
-        'i', 'j', 'k', 'l', 'm', 'n', 'o', 'p',
-    ];
-
-    assert(cmp(r1, r2) == 0);
-    assert(cmp(r1[1 .. $], r2[1 .. $]) == 0);
-    assert(cmp(r1[0 .. $ - 1], r2[0 .. $ - 1]) == 0);
-    assert(cmp(r1[0 .. 8], r2[0 .. 8]) == 0);
+    return r1.length < r2.length ? -1 : memcmp(r1.ptr, r2.ptr, r1.length);
 }
 
 /**
@@ -362,13 +328,13 @@ do
 {
     const ubyte[9] haystack = ['a', 'b', 'c', 'd', 'e', 'f', 'b', 'g', 'h'];
 
-    assert(cmp(find(haystack, 'a'), haystack[]) == 0);
-    assert(cmp(find(haystack, 'b'), haystack[1 .. $]) == 0);
-    assert(cmp(find(haystack, 'c'), haystack[2 .. $]) == 0);
-    assert(cmp(find(haystack, 'd'), haystack[3 .. $]) == 0);
-    assert(cmp(find(haystack, 'e'), haystack[4 .. $]) == 0);
-    assert(cmp(find(haystack, 'f'), haystack[5 .. $]) == 0);
-    assert(cmp(find(haystack, 'h'), haystack[8 .. $]) == 0);
+    assert(equal(find(haystack, 'a'), haystack[]));
+    assert(equal(find(haystack, 'b'), haystack[1 .. $]));
+    assert(equal(find(haystack, 'c'), haystack[2 .. $]));
+    assert(equal(find(haystack, 'd'), haystack[3 .. $]));
+    assert(equal(find(haystack, 'e'), haystack[4 .. $]));
+    assert(equal(find(haystack, 'f'), haystack[5 .. $]));
+    assert(equal(find(haystack, 'h'), haystack[8 .. $]));
     assert(find(haystack, 'i').length == 0);
 
     assert(find(null, 'a').length == 0);
@@ -441,10 +407,66 @@ do
 ///
 @nogc nothrow pure @safe unittest
 {
-    assert(cmp(findNullTerminated("abcdef\0gh"), "abcdef") == 0);
-    assert(cmp(findNullTerminated("\0garbage"), "") == 0);
-    assert(cmp(findNullTerminated("\0"), "") == 0);
-    assert(cmp(findNullTerminated("cstring\0"), "cstring") == 0);
+    assert(equal(findNullTerminated("abcdef\0gh"), "abcdef"));
+    assert(equal(findNullTerminated("\0garbage"), ""));
+    assert(equal(findNullTerminated("\0"), ""));
+    assert(equal(findNullTerminated("cstring\0"), "cstring"));
     assert(findNullTerminated(null) is null);
     assert(findNullTerminated("abcdef") is null);
 }
+
+/**
+ * Compares two memory areas $(D_PARAM r1) and $(D_PARAM r2) for equality.
+ *
+ * Params:
+ *  haystack = First memory block.
+ *  needle   = First memory block.
+ *
+ * Returns: $(D_KEYWORD true) if $(D_PARAM r1) and $(D_PARAM r2) are equal,
+ *          $(D_KEYWORD false) otherwise.
+ */
+bool equal(const void[] r1, const void[] r2) @nogc nothrow pure @trusted
+in
+{
+    assert(r1.length == 0 || r1.ptr !is null);
+    assert(r2.length == 0 || r2.ptr !is null);
+}
+do
+{
+    version (TanyaNative)
+    {
+        return equalMemory(r1, r2);
+    }
+    else
+    {
+        return r1.length == r2.length
+            && memcmp(r1.ptr, r2.ptr, r1.length) == 0;
+    }
+}
+
+///
+@nogc nothrow pure @safe unittest
+{
+    assert(equal("asdf", "asdf"));
+    assert(!equal("asd", "asdf"));
+    assert(!equal("asdf", "asd"));
+    assert(!equal("asdf", "qwer"));
+}
+
+// Compares unanligned memory
+@nogc nothrow pure @safe unittest
+{
+    ubyte[16] r1 = [
+        'a', 'b', 'c', 'd', 'e', 'f', 'g', 'h',
+        'i', 'j', 'k', 'l', 'm', 'n', 'o', 'p',
+    ];
+    ubyte[16] r2 = [
+        'a', 'b', 'c', 'd', 'e', 'f', 'g', 'h',
+        'i', 'j', 'k', 'l', 'm', 'n', 'o', 'p',
+    ];
+
+    assert(equal(r1, r2));
+    assert(equal(r1[1 .. $], r2[1 .. $]));
+    assert(equal(r1[0 .. $ - 1], r2[0 .. $ - 1]));
+    assert(equal(r1[0 .. 8], r2[0 .. 8]));
+}