add support for branch comparisons using the TST instruction

... and bump vale to pull in the recent commit that adds support for them.
This will be needed for repeated enclave entry/return.

tools/vale

@@ -1 +1 @@
-Subproject commit 22ce0745df01ac11661b54ad28e1b063beb32e6d
+Subproject commit b5f9c87e71d2af6b87a486bbb221b5f393186b30

verified/ARMdef.dfy

@@ -252,7 +252,7 @@ datatype ins =
 //-----------------------------------------------------------------------------
 // Code Representation
 //-----------------------------------------------------------------------------
-datatype ocmp = OEq | ONe | OLe | OGe | OLt | OGt
+datatype ocmp = OEq | ONe | OLe | OGe | OLt | OGt | OTstEq | OTstNe
 datatype obool = OCmp(cmp:ocmp, o1:operand, o2:operand)
 
 datatype codes = CNil | va_CCons(hd:code, tl:codes)
@@ -833,6 +833,8 @@ function evalCmp(c:ocmp, i1:word, i2:word):bool
     case OGe => i1 >= i2
     case OLt => i1 <  i2
     case OGt => i1 >  i2
+    case OTstEq => BitwiseAnd(i1, i2) == 0
+    case OTstNe => BitwiseAnd(i1, i2) != 0
 }
 
 function evalOBool(s:state, o:obool):bool

verified/ARMprint.dfy

@@ -34,6 +34,8 @@ function method cmpNot(c:ocmp):ocmp
         case OGe => OLt
         case OLt => OGe
         case OGt => OLe
+        case OTstEq => OTstNe
+        case OTstNe => OTstEq
 }
 
 method printBcc(c:ocmp)
@@ -45,6 +47,17 @@ method printBcc(c:ocmp)
         case OGe => print("  BGE ");
         case OLt => print("  BLT ");
         case OGt => print("  BGT ");
+        case OTstEq => print("  BEQ ");
+        case OTstNe => print("  BNE ");
+}
+
+method printCmp(c:ocmp, o1:operand, o2:operand)
+{
+    if c == OTstEq || c == OTstNe {
+        printIns2Op("TST", o1, o2);
+    } else {
+        printIns2Op("CMP", o1, o2);
+    }
 }
 
 /*
@@ -276,7 +289,7 @@ method printCode(c:code, n:int) returns(n':int)
             var false_branch := n;
             var end_of_block := n + 1;
             // Do comparison
-            printIns2Op("CMP", ifb.o1, ifb.o2);
+            printCmp(ifb.cmp, ifb.o1, ifb.o2);
             // Branch to false branch if cond is false
             printBcc(cmpNot(ifb.cmp)); printLabel(false_branch); nl();
             // True branch
@@ -297,7 +310,7 @@ method printCode(c:code, n:int) returns(n':int)
           printLabel(n1); print(":"); nl();
           n' := printCode(loop, n + 2);
           printLabel(n2); print(":"); nl();
-          printIns2Op("CMP", b.o1, b.o2);
+          printCmp(b.cmp, b.o1, b.o2);
           printBcc(b.cmp); printLabel(n1); nl();
         }
     }

verified/ARMspartan.dfy

@@ -65,6 +65,8 @@ function method va_cmp_le(o1:operand, o2:operand):obool { OCmp(OLe, o1, o2) }
 function method va_cmp_ge(o1:operand, o2:operand):obool { OCmp(OGe, o1, o2) }
 function method va_cmp_lt(o1:operand, o2:operand):obool { OCmp(OLt, o1, o2) }
 function method va_cmp_gt(o1:operand, o2:operand):obool { OCmp(OGt, o1, o2) }
+function method va_cmp_tst_eq(o1:operand, o2:operand):obool { OCmp(OTstEq, o1, o2) }
+function method va_cmp_tst_ne(o1:operand, o2:operand):obool { OCmp(OTstNe, o1, o2) }
 
 function method va_Block(block:codes):code { Block(block) }
 function method va_IfElse(ifb:obool, ift:code, iff:code):code { IfElse(ifb, ift, iff) }