1 files changed, 70 insertions, 0 deletions
diff --git a/zap/source/amd64/mth/abs.S b/zap/source/amd64/mth/abs.S
new file mode 100644
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+++ b/zap/source/amd64/mth/abs.S
@@ -0,0 +1,70 @@
+# Copyright 2022 Gabriel Jensen.
+# This Source Code Form is subject to the terms of the Mozilla Public License, v. 2.0.
+# If a copy of the MPL was not distributed with this file, You can obtain one at https://mozilla.org/MPL/2.0/.
+
+.globl zap_abs_c
+.globl zap_abs_i
+.globl zap_abs_l
+.globl zap_abs_ll
+.globl zap_abs_s
+.globl zap_abs_sc
+
+zap_abs_i:
+# The input value:
+#define val %edi
+# Inverted value of the input:
+#define inv %eax
+	movl val,inv   # inv = val
+	negl inv       # inv = -inv     // Invert the copy of the input value. This also tests the sign of the value.
+	               # . if (inv > 0x0)
+	cmovsl val,inv # val = inv      // If it was positive, just return the unmodified input.
+	ret            # return val     // Otherwise, return the inverted value.
+
+#undef val
+#undef inv
+
+zap_abs_l:
+zap_abs_ll:
+# The input value:
+#define val %rdi
+# Inverted value of the input:
+#define inv %rax
+	movq val,inv   # inv = val
+	negq inv       # inv = -inv
+	               # . if (inv > 0x0)
+	cmovsq val,inv # val = inv
+	ret            # return val
+
+#undef val
+#undef inv
+
+zap_abs_s:
+# The input value:
+#define val %di
+# Inverted value of the input:
+#define inv %ax
+	movw val,inv   # inv = val
+	negw inv       # inv = -inv
+	               # . if (inv > 0x0)
+	cmovsw val,inv # val = inv
+	ret            # return val
+
+#undef val
+#undef inv
+
+zap_abs_c:
+zap_abs_sc:
+# The input value:
+#define val  %dil
+#define val2 %di
+# Inverted value of the input:
+#define inv  %al
+#define inv2 %ax
+	movb val,inv     # inv = val
+	negb inv         # inv = -inv
+	                 # . if (inv > 0x0)
+	cmovsw val2,inv2 # val = inv
+	ret              # return val
+
+#undef val
+#undef inv