Merge pull request #134 from sampsyo/ssa-tweaks

More tests and a fix for SSA conversion (from #119)

examples/test/ssa_roundtrip/argwrite.bril

@@ -0,0 +1,9 @@
+# ARGS: 3
+@main(a: int) {
+  cond: bool = const true;
+  br cond .here .there;
+.here:
+  a: int = const 5;
+.there:
+  print a;
+}

examples/test/ssa_roundtrip/argwrite.out

@@ -0,0 +1 @@
+5

examples/test/ssa_roundtrip/if-const.bril

@@ -0,0 +1,14 @@
+@main() {
+    cond: bool = const true;
+    br cond .true .false;
+.true:
+    a: int = const 0;
+    jmp .zexit;
+.false:
+    b: int = const 1;
+    jmp .zexit;
+# zexit to trigger a bug in to_ssa.py that depends on
+# the order that basic blocks get renamed.
+.zexit:
+    print a;
+}

examples/test/ssa_roundtrip/if-const.out

@@ -0,0 +1 @@
+0

examples/test/ssa_roundtrip/if-ssa.bril.BROKEN

@@ -0,0 +1,17 @@
+# ARGS: true
+@main(cond: bool) {
+.entry:
+    a.1: int = const 47;
+    br cond .left .right;
+.left:
+    a.2: int = add a.1 a.1;
+    jmp .zexit;
+.right:
+    a.3: int = mul a.1 a.1;
+    jmp .zexit;
+# zexit to trigger a bug in to_ssa.py that depends on
+# the order that basic blocks get renamed.
+.zexit:
+    a.4: int = phi .left a.2 .right a.3;
+    print a.4;
+}

examples/test/ssa_roundtrip/if-ssa.out

@@ -0,0 +1 @@
+94

examples/test/ssa_roundtrip/if.bril

@@ -0,0 +1,14 @@
+# ARGS: false
+@main(cond: bool) {
+.entry:
+    a: int = const 47;
+    br cond .left .right;
+.left:
+    a: int = add a a;
+    jmp .exit;
+.right:
+    a: int = mul a a;
+    jmp .exit;
+.exit:
+    print a;
+}

examples/test/ssa_roundtrip/if.out

@@ -0,0 +1 @@
+2209

examples/test/ssa_roundtrip/loop-branch.bril.BROKEN

@@ -0,0 +1,24 @@
+@func(): int {
+    n: int = const 5;
+    ret n;
+}
+
+@loop(infinite: bool, print: bool) {
+.entry:
+.loop.header:
+    br infinite .loop.body .loop.end;
+.loop.body:
+    br print .loop.print .loop.next;
+.loop.print:
+    v: int = call @func;
+    print v;
+.loop.next:
+    jmp .loop.header;
+.loop.end:
+}
+
+@main() {
+  infinite: bool = const false;
+  print: bool = const true;
+  call @loop infinite print;
+}

examples/test/ssa_roundtrip/loop.bril

@@ -0,0 +1,14 @@
+@main {
+.entry:
+    i: int = const 1;
+    jmp .loop;
+.loop:
+    max: int = const 10;
+    cond: bool = lt i max;
+    br cond .body .exit;
+.body:
+    i: int = add i i;
+    jmp .loop;
+.exit:
+    print i;
+}

examples/test/ssa_roundtrip/loop.out

@@ -0,0 +1 @@
+16

examples/test/ssa_roundtrip/selfloop.bril

@@ -0,0 +1,14 @@
+@main {
+.entry:
+  one: int = const 1;
+  zero: int = const 0;
+  x: int = const 5;
+.loop:
+  x: int = sub x one;
+  done: bool = eq x zero;
+.br:
+  br done .exit .loop;
+.exit:
+  print x;
+  ret;
+}

examples/test/ssa_roundtrip/selfloop.out

@@ -0,0 +1 @@
+0

examples/test/ssa_roundtrip/turnt.toml

@@ -0,0 +1 @@
+command = "bril2json < {filename} | python ../../to_ssa.py | python ../../from_ssa.py | python ../../tdce.py | brili {args}"

examples/test/ssa_roundtrip/while.bril

@@ -0,0 +1,13 @@
+# ARGS: 5
+@main(a: int) {
+.while.cond:
+  zero: int = const 0;
+  is_term: bool = eq a zero;
+  br is_term .while.finish .while.body;
+.while.body:
+  one: int = const 1;
+  a: int = sub a one;
+  jmp .while.cond;
+.while.finish:
+  print a;
+}

examples/test/ssa_roundtrip/while.out

@@ -0,0 +1 @@
+0

examples/test/to_ssa/if-const.out

@@ -9,7 +9,7 @@
   b.0: int = const 1;
   jmp .zexit;
 .zexit:
-  b.1: int = phi b.0 b.0 .false .true;
+  b.1: int = phi b.0 __undefined .false .true;
   a.1: int = phi __undefined a.0 .false .true;
   print a.1;
   ret;

examples/test/to_ssa/if-ssa.out

@@ -10,7 +10,7 @@
   jmp .zexit;
 .zexit:
   a.3.1: int = phi __undefined a.3.0 .left .right;
-  a.2.1: int = phi a.2.0 a.2.0 .left .right;
+  a.2.1: int = phi a.2.0 __undefined .left .right;
   a.4.0: int = phi a.2.1 a.3.1 .left .right;
   print a.4.0;
   ret;

examples/test/to_ssa/loop-branch.bril

@@ -0,0 +1,24 @@
+@func(): int {
+    n: int = const 5;
+    ret n;
+}
+
+@loop(infinite: bool, print: bool) {
+.entry:
+.loop.header:
+    br infinite .loop.body .loop.end;
+.loop.body:
+    br print .loop.print .loop.next;
+.loop.print:
+    v: int = call @func;
+    print v;
+.loop.next:
+    jmp .loop.header;
+.loop.end:
+}
+
+@main() {
+  infinite: bool = const false;
+  print: bool = const true;
+  call @loop infinite print;
+}

examples/test/to_ssa/loop-branch.out

@@ -0,0 +1,30 @@
+@func: int {
+.b1:
+  n.0: int = const 5;
+  ret n.0;
+}
+@loop(infinite: bool, print: bool) {
+.entry:
+  jmp .loop.header;
+.loop.header:
+  v.0: int = phi __undefined v.1 .entry .loop.next;
+  br infinite .loop.body .loop.end;
+.loop.body:
+  br print .loop.print .loop.next;
+.loop.print:
+  v.2: int = call @func;
+  print v.2;
+  jmp .loop.next;
+.loop.next:
+  v.1: int = phi v.0 v.2 .loop.body .loop.print;
+  jmp .loop.header;
+.loop.end:
+  ret;
+}
+@main {
+.b1:
+  infinite.0: bool = const false;
+  print.0: bool = const true;
+  call @loop infinite.0 print.0;
+  ret;
+}

examples/to_ssa.py

@@ -4,7 +4,7 @@
 
 from cfg import block_map, successors, add_terminators, add_entry, reassemble
 from form_blocks import form_blocks
-from dom import get_dom, dom_fronts, dom_tree, map_inv
+from dom import get_dom, dom_fronts, dom_tree
 
 
 def def_blocks(blocks):
@@ -83,6 +83,7 @@ def _rename(block):
             _rename(b)
 
         # Restore stacks.
+        stack.clear()
         stack.update(old_stack)
 
     entry = list(blocks.keys())[0]
@@ -91,7 +92,6 @@ def _rename(block):
     return phi_args, phi_dests
 
 
-
 def insert_phis(blocks, phi_args, phi_dests, types):
     for block, instrs in blocks.items():
         for dest, pairs in sorted(phi_args[block].items()):
@@ -121,7 +121,6 @@ def func_to_ssa(func):
     add_entry(blocks)
     add_terminators(blocks)
     succ = {name: successors(block[-1]) for name, block in blocks.items()}
-    pred = map_inv(succ)
     dom = get_dom(succ, list(blocks.keys())[0])
 
     df = dom_fronts(dom, succ)