From 953c08839f330eb8e3c04eb8829a61cad21886a9 Mon Sep 17 00:00:00 2001
From: David Given <dg@cowlark.com>
Date: Sun, 20 Nov 2016 12:53:44 +0100
Subject: [PATCH] inn works now; add a helper for it.

---
 mach/powerpc/libem/build.lua |  1 +
 mach/powerpc/libem/inn.s     | 26 ++++++++++++
 mach/proto/mcg/treebuilder.c |  9 ++---
 plat/qemuppc/tests/inn_e.e   | 76 ++++++++++++++++++++++++++++++++++++
 4 files changed, 107 insertions(+), 5 deletions(-)
 create mode 100644 mach/powerpc/libem/inn.s
 create mode 100644 plat/qemuppc/tests/inn_e.e

diff --git a/mach/powerpc/libem/build.lua b/mach/powerpc/libem/build.lua
index dd9ec7542..318be381d 100644
--- a/mach/powerpc/libem/build.lua
+++ b/mach/powerpc/libem/build.lua
@@ -8,6 +8,7 @@ for _, plat in ipairs(vars.plats) do
 		name = "lib_"..plat,
 		srcs = {
 			"./*.s",
+			"./*.e",
 		},
 		vars = { plat = plat },
 		deps = {
diff --git a/mach/powerpc/libem/inn.s b/mach/powerpc/libem/inn.s
new file mode 100644
index 000000000..f5ae4c63e
--- /dev/null
+++ b/mach/powerpc/libem/inn.s
@@ -0,0 +1,26 @@
+#include "powerpc.h"
+
+.sect .text
+
+/* Tests a bit in a bitset on the stack.
+ *
+ * Stack: ( bitset bitnum setsize -- bool )
+ */
+
+.define .inn
+.inn:
+    lwz r3, 0(sp)       /* r3 = size (bytes) */
+    lwz r4, 4(sp)       /* r4 = bit number */
+    addi r5, sp, 8      /* r5 = base address of bit set */
+
+    srawi r6, r4, 3     /* r6 = byte address into set */
+    andi. r7, r4, 7     /* r7 = bit within byte */
+
+    lbzx r8, r5, r6     /* r8 = individual byte from set */
+    sraw r8, r8, r7
+    rlwinm r8, r8, 0, 31, 31
+
+    addi sp, sp, 8      /* retract over the two words */
+    add sp, sp, r3      /* retract over bitfield */
+    stwu r8, -4(sp)     /* push result */
+    bclr ALWAYS, 0, 0   /* return */
diff --git a/mach/proto/mcg/treebuilder.c b/mach/proto/mcg/treebuilder.c
index 18e77c94a..2ead527fc 100644
--- a/mach/proto/mcg/treebuilder.c
+++ b/mach/proto/mcg/treebuilder.c
@@ -1447,12 +1447,11 @@ static void insn_ivalue(int opcode, arith value)
          * (Modula-2 bitset support, I believe). Leave them until leter. */
         case op_inn:
         {
-            appendir(
-                new_ir1(
-                    IR_CALL, 0,
-                    new_labelir(".unimplemented")
-                )
+            push(
+                new_wordir(value)
             );
+
+            helper_function(".inn");
             break;
         }
 
diff --git a/plat/qemuppc/tests/inn_e.e b/plat/qemuppc/tests/inn_e.e
new file mode 100644
index 000000000..4e53b35c5
--- /dev/null
+++ b/plat/qemuppc/tests/inn_e.e
@@ -0,0 +1,76 @@
+#
+    mes 2, 4, 4
+
+    exp $_m_a_i_n
+    pro $_m_a_i_n, 0
+
+    /* Test non-existent bit */
+
+.1
+    rom 0I1, 0I1, 0I1, 0I1
+    loe .1
+    loc 1       /* bit number */
+    inn 4
+    zeq *1
+
+    loc __LINE__
+    cal $fail
+    ass 4
+1
+
+    /* Test existent bit */
+
+.2
+    rom 2I1, 0I1, 0I1, 0I1
+    loe .2
+    loc 1       /* bit number */
+    inn 4
+    zne *2
+
+    loc __LINE__
+    cal $fail
+    ass 4
+2
+
+    /* Test non-existent high bit */
+
+.3
+    rom 0I1, 0I1, 0I1, 0I1
+    rom 0I1, 0I1, 0I1, 0I1
+.31
+    rom 33      /* to defeat constant folding */
+
+    lae .3
+    loi 8
+    loe .31     /* bit number */
+    inn 8
+    zeq *3
+
+    loc __LINE__
+    cal $fail
+    ass 4
+3
+
+    /* Test existent high bit */
+
+.4
+    rom 0I1, 0I1, 0I1, 0I1
+    rom 2I1, 0I1, 0I1, 0I1
+.41
+    rom 33      /* to defeat constant folding */
+
+    lae .4
+    loi 8
+    loe .41     /* bit number */
+    inn 8
+    zne *4
+
+    loc __LINE__
+    cal $fail
+    ass 4
+4
+
+    cal $finished
+    ret 0
+    
+    end