From 0ce368324ed41b03f37c9a8dcd4eba5631fc7447 Mon Sep 17 00:00:00 2001
From: David Given <dg@cowlark.com>
Date: Mon, 10 Sep 2018 23:37:28 +0200
Subject: [PATCH] Add the bitset helpers. We now have enough helpers for the
 tests to run (and massively fail).

---
 mach/mips/libem/and.s | 30 ++++++++++++++++++++++++++++++
 mach/mips/libem/com.s | 27 +++++++++++++++++++++++++++
 mach/mips/libem/ior.s | 30 ++++++++++++++++++++++++++++++
 mach/mips/libem/set.s | 37 +++++++++++++++++++++++++++++++++++++
 mach/mips/libem/zer.s | 24 ++++++++++++++++++++++++
 5 files changed, 148 insertions(+)
 create mode 100644 mach/mips/libem/and.s
 create mode 100644 mach/mips/libem/com.s
 create mode 100644 mach/mips/libem/ior.s
 create mode 100644 mach/mips/libem/set.s
 create mode 100644 mach/mips/libem/zer.s

diff --git a/mach/mips/libem/and.s b/mach/mips/libem/and.s
new file mode 100644
index 000000000..5f0eacb2c
--- /dev/null
+++ b/mach/mips/libem/and.s
@@ -0,0 +1,30 @@
+#
+.sect .text; .sect .rom; .sect .data; .sect .bss
+
+/*
+ * Set intersection.
+ * Stack: ( a b size -- a&b )
+ */
+
+.sect .text
+.define .and
+.and:
+	lw r4, 0(sp)        ! r4 = size
+	addiu sp, sp, 4     ! sp points at b
+	addu r5, sp, r4     ! r5 points at a
+	srl r4, r4, 2       ! r4 = count of words
+
+1:
+	lw at, 0(r5)        ! load a
+	lw r6, 0(sp)        ! load b
+	and at, at, r6      ! combine
+	sw at, 0(r5)        ! write back to a
+	addiu r5, r5, 4
+	addiu sp, sp, 4
+	addiu r4, r4, -1
+	bne r4, zero, 1b
+	nop
+
+	jr ra
+	nop
+
diff --git a/mach/mips/libem/com.s b/mach/mips/libem/com.s
new file mode 100644
index 000000000..fae0d64e5
--- /dev/null
+++ b/mach/mips/libem/com.s
@@ -0,0 +1,27 @@
+#
+.sect .text; .sect .rom; .sect .data; .sect .bss
+
+/*
+ * Set complement.
+ * Stack: ( a size -- ~a )
+ */
+
+.sect .text
+.define .com
+.com:
+	lw r4, 0(sp)        ! r4 = size
+	addiu sp, sp, 4
+	mov r5, sp          ! r5 points to set
+	srl r4, r4, 2       ! r4 = word count
+
+1:
+	lw at, 0(r5)
+	nor at, zero, at
+	sw at, 0(r5)
+	addiu r5, r5, 4
+	addiu r4, r4, -1
+	bne r4, zero, 1b
+
+	jr ra
+	nop
+
diff --git a/mach/mips/libem/ior.s b/mach/mips/libem/ior.s
new file mode 100644
index 000000000..df2828dfe
--- /dev/null
+++ b/mach/mips/libem/ior.s
@@ -0,0 +1,30 @@
+#
+.sect .text; .sect .rom; .sect .data; .sect .bss
+
+/*
+ * Set union.
+ * Stack: ( a b size -- a|b )
+ */
+
+.sect .text
+.define .ior
+.ior:
+	lw r4, 0(sp)        ! r4 = size
+	addiu sp, sp, 4     ! sp points at b
+	addu r5, sp, r4     ! r5 points at a
+	srl r4, r4, 2       ! r4 = count of words
+
+1:
+	lw at, 0(r5)        ! load a
+	lw r6, 0(sp)        ! load b
+	or at, at, r6       ! combine
+	sw at, 0(r5)        ! write back to a
+	addiu r5, r5, 4
+	addiu sp, sp, 4
+	addiu r4, r4, -1
+	bne r4, zero, 1b
+	nop
+
+	jr ra
+	nop
+
diff --git a/mach/mips/libem/set.s b/mach/mips/libem/set.s
new file mode 100644
index 000000000..01a6ff654
--- /dev/null
+++ b/mach/mips/libem/set.s
@@ -0,0 +1,37 @@
+#
+.sect .text; .sect .rom; .sect .data; .sect .bss
+
+/*
+ * Create singleton set.
+ * Stack: ( bitnumber size -- set )
+ */
+
+.sect .text
+.define .set
+.set:
+	lw r4, 0(sp)        ! r4 = size
+	lw r5, 4(sp)        ! r5 = bit number
+	addiu sp, sp, 4
+	srl r4, r4, 2       ! r4 = word count
+
+	! Create an empty set.
+
+1:
+	addiu sp, sp, -4
+	sw zero, 0(sp)
+	addiu r4, r4, -1
+	bne r4, zero, 1b
+
+	! sp now points at the set.
+
+	srl r6, r5, 3       ! r6 = offset of word in set
+	addu r6, sp, r6     ! r6 = address of word in set
+
+	ext r7, r5, 0, 3    ! r7 = bit number within word
+	li r8, 1
+	sllv r8, r8, r7     ! r8 = word with 1 set
+	sw r8, 0(r6)        ! write to set
+
+	jr ra
+	nop
+
diff --git a/mach/mips/libem/zer.s b/mach/mips/libem/zer.s
new file mode 100644
index 000000000..6941d340b
--- /dev/null
+++ b/mach/mips/libem/zer.s
@@ -0,0 +1,24 @@
+#
+.sect .text; .sect .rom; .sect .data; .sect .bss
+
+/*
+ * Create empty set.
+ * Stack: ( size -- set )
+ */
+
+.sect .text
+.define .zer
+.zer:
+	lw r4, 0(sp)        ! r4 = size
+	addiu sp, sp, 4
+	srl r4, r4, 2       ! r4 = word count
+
+1:
+	addiu sp, sp, -4
+	sw zero, 0(sp)
+	addiu r4, r4, -1
+	bne r4, zero, 1b
+
+	jr ra
+	nop
+