split out instructions from openpower/isa/prefix_codes.mdwn

diff --git a/openpower/isa/prefix_codes.mdwn b/openpower/isa/prefix_codes.mdwn
index 8d6415436cbc9cc6f5051334751e07b37812ba19..0317fd908f4258610ba4e2baaff05d560d62ff3a 100644 (file)
--- a/openpower/isa/prefix_codes.mdwn
+++ b/openpower/isa/prefix_codes.mdwn
@@ -1,83 +1,3 @@
 <!-- https://libre-soc.org/openpower/prefix_codes/ -->
 
-# [DRAFT] Prefix-code decode
-
-VA-Form
-
-* pcdec. RT,RA,RB,RC
-
-Pseudo-code:
-
-    tree[0:63] <- (RB)
-    mode <- tree[62:63]
-    tree[62:63] <- 0
-    ra_used <- 0b0
-    in_bits[0:63] <- (RC|0)
-    if in_bits = 0 then
-        in_bits[0:63] <- 1
-    orig_in_bits <- in_bits
-    tree_index <- 1
-    found <- 0b0
-    hit_end <- 0b0
-    do bit_length = 1 to 6
-        in_bit <- in_bits[63]
-        if in_bits = 1 then
-            if ra_used | (_RA = 0) then
-                hit_end <- 0b1
-                leave
-            ra_used <- 0b1
-            in_bit <- (RA)[63]
-            in_bits <- 0b1 || (RA)[0:62]
-        else
-            in_bits <- 0b0 || in_bits[0:62]
-        # walk the binary tree in `tree` from parent to the selected child
-        tree_index <- tree_index * 2
-        if in_bit = 1 then
-            tree_index <- tree_index + 1
-        if tree_index < 64 then
-            if tree[63 - tree_index] then
-                found <- 0b1
-                leave
-    compressed_index <- 0
-    do i = 0 to 127
-        possible <- 1
-        j <- i
-        do while j >= 4
-            j <- j / 2
-            if tree[63 - j] then
-                possible <- 0
-                leave
-        if i = tree_index then
-            leave
-        else if i >= 64 then
-            compressed_index <- compressed_index + possible
-        else if tree[63 - i] = 1 then
-            compressed_index <- compressed_index + possible
-    switch(mode)
-        case(0):
-            RT[0:63] <- tree_index
-            if ¬found then
-                in_bits <- orig_in_bits
-                ra_used <- 0b0
-        case(1):
-            RT[0:63] <- tree_index
-            if hit_end then
-                in_bits <- orig_in_bits
-                ra_used <- 0b0
-        case(2):
-            RT[0:63] <- compressed_index
-            if ¬found then
-                in_bits <- orig_in_bits
-                ra_used <- 0b0
-                RT[0:63] <- tree_index
-        default:
-            RT[0:63] <- compressed_index
-            if hit_end then
-                in_bits <- orig_in_bits
-                ra_used <- 0b0
-    RS <- in_bits
-    CR0 <- ra_used || (tree_index >= 64) || found || hit_end
-
-Special Registers Altered:
-
-    CR0
+[[!inline pagenames="openpower/isa/prefix_codes/pcdec." raw="yes"]]

diff --git a/openpower/isa/prefix_codes/pcdec..mdwn b/openpower/isa/prefix_codes/pcdec..mdwn
new file mode 100644 (file)
index 0000000..922de2a
--- /dev/null
+++ b/openpower/isa/prefix_codes/pcdec..mdwn
@@ -0,0 +1,13 @@
+# [DRAFT] Prefix-code decode
+
+VA-Form
+
+* pcdec. RT,RA,RB,RC
+
+Pseudo-code:
+
+[[!inline pagenames="openpower/isa/prefix_codes/pcdec._code" raw="yes"]]
+
+Special Registers Altered:
+
+    CR0

diff --git a/openpower/isa/prefix_codes/pcdec._code.mdwn b/openpower/isa/prefix_codes/pcdec._code.mdwn
new file mode 100644 (file)
index 0000000..cd3ddc3
--- /dev/null
+++ b/openpower/isa/prefix_codes/pcdec._code.mdwn
@@ -0,0 +1,69 @@
+    tree[0:63] <- (RB)
+    mode <- tree[62:63]
+    tree[62:63] <- 0
+    ra_used <- 0b0
+    in_bits[0:63] <- (RC|0)
+    if in_bits = 0 then
+        in_bits[0:63] <- 1
+    orig_in_bits <- in_bits
+    tree_index <- 1
+    found <- 0b0
+    hit_end <- 0b0
+    do bit_length = 1 to 6
+        in_bit <- in_bits[63]
+        if in_bits = 1 then
+            if ra_used | (_RA = 0) then
+                hit_end <- 0b1
+                leave
+            ra_used <- 0b1
+            in_bit <- (RA)[63]
+            in_bits <- 0b1 || (RA)[0:62]
+        else
+            in_bits <- 0b0 || in_bits[0:62]
+        # walk the binary tree in `tree` from parent to the selected child
+        tree_index <- tree_index * 2
+        if in_bit = 1 then
+            tree_index <- tree_index + 1
+        if tree_index < 64 then
+            if tree[63 - tree_index] then
+                found <- 0b1
+                leave
+    compressed_index <- 0
+    do i = 0 to 127
+        possible <- 1
+        j <- i
+        do while j >= 4
+            j <- j / 2
+            if tree[63 - j] then
+                possible <- 0
+                leave
+        if i = tree_index then
+            leave
+        else if i >= 64 then
+            compressed_index <- compressed_index + possible
+        else if tree[63 - i] = 1 then
+            compressed_index <- compressed_index + possible
+    switch(mode)
+        case(0):
+            RT[0:63] <- tree_index
+            if ¬found then
+                in_bits <- orig_in_bits
+                ra_used <- 0b0
+        case(1):
+            RT[0:63] <- tree_index
+            if hit_end then
+                in_bits <- orig_in_bits
+                ra_used <- 0b0
+        case(2):
+            RT[0:63] <- compressed_index
+            if ¬found then
+                in_bits <- orig_in_bits
+                ra_used <- 0b0
+                RT[0:63] <- tree_index
+        default:
+            RT[0:63] <- compressed_index
+            if hit_end then
+                in_bits <- orig_in_bits
+                ra_used <- 0b0
+    RS <- in_bits
+    CR0 <- ra_used || (tree_index >= 64) || found || hit_end