Add utils/ABITest, my ABI test generation tool.

 - Mostly written as an entertaining exercise in enumerating large or
   (countably, naturally) infinite sets. But hey, its useful too!

 - Idea is to number all C-types so that the N-th type can quickly be
   computed, with a good deal of flexibility about what types to
   include, and taking some care so that the (N+1)-th type is
   interestingly different from the N-th type. For example, using the
   default generator, the 1,000,000-th function type is:
--
typedef _Complex int T0;
typedef char T1 __attribute__ ((vector_size (4)));
typedef int T2 __attribute__ ((vector_size (4)));
T2 fn1000000(T0 arg0, signed long long arg1, T1 arg2, T0 arg3);
--
   and the 1,000,001-th type is:
--
typedef _Complex char T0;
typedef _Complex char T2;
typedef struct T1 { T2 field0; T2 field1; T2 field2; } T1;
typedef struct T3 {  } T3;
unsigned short fn1000001(T0 arg0, T1 arg1, T3 arg2);
--

   Computing the 10^1600-th type takes a little less than 1s. :)


git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@62253 91177308-0d34-0410-b5e6-96231b3b80d8

1 files changed, 276 insertions, 0 deletions

diff --git a/utils/ABITest/Enumeration.py b/utils/ABITest/Enumeration.py
new file mode 100644
index 0000000000..47e47026db
--- /dev/null
+++ b/utils/ABITest/Enumeration.py
@@ -0,0 +1,276 @@
+"""Utilities for enumeration of finite and countably infinite sets.
+"""
+###
+# Countable iteration
+
+# Simplifies some calculations
+class Aleph0(int):
+    _singleton = None
+    def __new__(type):
+        if type._singleton is None:
+            type._singleton = int.__new__(type)
+        return type._singleton
+    def __repr__(self): return '<aleph0>'
+    def __str__(self): return 'inf'
+    
+    def __cmp__(self, b):
+        return 1
+
+    def __sub__(self, b):
+        raise ValueError,"Cannot subtract aleph0"
+    __rsub__ = __sub__
+
+    def __add__(self, b): 
+        return self
+    __radd__ = __add__
+
+    def __mul__(self, b): 
+        if b == 0: return b            
+        return self
+    __rmul__ = __mul__
+
+    def __floordiv__(self, b):
+        if b == 0: raise ZeroDivisionError
+        return self
+    __rfloordiv__ = __floordiv__
+    __truediv__ = __floordiv__
+    __rtuediv__ = __floordiv__
+    __div__ = __floordiv__
+    __rdiv__ = __floordiv__
+
+    def __pow__(self, b):
+        if b == 0: return 1
+        return self
+aleph0 = Aleph0()
+
+def base(line):
+    return line*(line+1)//2
+
+def pairToN((x,y)):
+    line,index = x+y,y
+    return base(line)+index
+
+def getNthPairInfo(N):
+    # Avoid various singularities
+    if N==0:
+        return (0,0)
+
+    # Gallop to find bounds for line
+    line = 1
+    next = 2
+    while base(next)<=N:
+        line = next
+        next = line << 1
+    
+    # Binary search for starting line
+    lo = line
+    hi = line<<1
+    while lo + 1 != hi:
+        #assert base(lo) <= N < base(hi)
+        mid = (lo + hi)>>1
+        if base(mid)<=N:
+            lo = mid
+        else:
+            hi = mid
+
+    line = lo
+    return line, N - base(line)
+
+def getNthPair(N):
+    line,index = getNthPairInfo(N)
+    return (line - index, index)
+
+def getNthPairBounded(N,W=aleph0,H=aleph0,useDivmod=False):
+    """getNthPairBounded(N, W, H) -> (x, y)
+    
+    Return the N-th pair such that 0 <= x < W and 0 <= y < H."""
+
+    if W <= 0 or H <= 0:
+        raise ValueError,"Invalid bounds"
+    elif N >= W*H:
+        raise ValueError,"Invalid input (out of bounds)"
+
+    # Simple case...
+    if W is aleph0 and H is aleph0:
+        return getNthPair(N)
+
+    # Otherwise simplify by assuming W < H
+    if H < W:
+        x,y = getNthPairBounded(N,H,W,useDivmod=useDivmod)
+        return y,x
+
+    if useDivmod:
+        return N%W,N//W
+    else:
+        # Conceptually we want to slide a diagonal line across a
+        # rectangle. This gives more interesting results for large
+        # bounds than using divmod.
+        
+        # If in lower left, just return as usual
+        cornerSize = base(W)
+        if N < cornerSize:
+            return getNthPair(N)
+
+        # Otherwise if in upper right, subtract from corner
+        if H is not aleph0:
+            M = W*H - N - 1
+            if M < cornerSize:
+                x,y = getNthPair(M)
+                return (W-1-x,H-1-y)
+
+        # Otherwise, compile line and index from number of times we
+        # wrap.
+        N = N - cornerSize
+        index,offset = N%W,N//W
+        # p = (W-1, 1+offset) + (-1,1)*index
+        return (W-1-index, 1+offset+index)
+def getNthPairBoundedChecked(N,W=aleph0,H=aleph0,useDivmod=False,GNP=getNthPairBounded):
+    x,y = GNP(N,W,H,useDivmod)
+    assert 0 <= x < W and 0 <= y < H
+    return x,y
+
+def getNthNTuple(N, W, H=aleph0, useLeftToRight=False):
+    """getNthNTuple(N, W, H) -> (x_0, x_1, ..., x_W)
+
+    Return the N-th W-tuple, where for 0 <= x_i < H."""
+
+    if useLeftToRight:
+        elts = [None]*W
+        for i in range(W):
+            elts[i],N = getNthPairBounded(N, H)
+        return tuple(elts)
+    else:
+        if W==0:
+            return ()
+        elif W==1:
+            return (N,)
+        elif W==2:
+            return getNthPairBounded(N, H, H)
+        else:
+            LW,RW = W//2, W - (W//2)
+            L,R = getNthPairBounded(N, H**LW, H**RW)
+            return (getNthNTuple(L,LW,H=H,useLeftToRight=useLeftToRight) + 
+                    getNthNTuple(R,RW,H=H,useLeftToRight=useLeftToRight))
+def getNthNTupleChecked(N, W, H=aleph0, useLeftToRight=False, GNT=getNthNTuple):
+    t = GNT(N,W,H,useLeftToRight)
+    assert len(t) == W
+    for i in t:
+        assert i < H
+    return t
+
+def getNthTuple(N, maxSize=aleph0, maxElement=aleph0, useDivmod=False, useLeftToRight=False):
+    """getNthTuple(N, maxSize, maxElement) -> x
+
+    Return the N-th tuple where len(x) < maxSize and for y in x, 0 <=
+    y < maxElement."""
+
+    # All zero sized tuples are isomorphic, don't ya know.
+    if N == 0:
+        return ()
+    N -= 1
+    if maxElement is not aleph0:
+        if maxSize is aleph0:
+            raise NotImplementedError,'Max element size without max size unhandled'
+        bounds = [maxElement**i for i in range(1, maxSize+1)]
+        S,M = getNthPairVariableBounds(N, bounds)
+    else:
+        S,M = getNthPairBounded(N, maxSize, useDivmod=useDivmod)
+    return getNthNTuple(M, S+1, maxElement, useLeftToRight=useLeftToRight)
+def getNthTupleChecked(N, maxSize=aleph0, maxElement=aleph0, 
+                       useDivmod=False, useLeftToRight=False, GNT=getNthTuple):
+    # FIXME: maxsize is inclusive
+    t = GNT(N,maxSize,maxElement,useDivmod,useLeftToRight)
+    assert len(t) <= maxSize
+    for i in t:
+        assert i < maxElement
+    return t
+
+def getNthPairVariableBounds(N, bounds):
+    """getNthPairVariableBounds(N, bounds) -> (x, y)
+
+    Given a finite list of bounds (which may be finite or aleph0),
+    return the N-th pair such that 0 <= x < len(bounds) and 0 <= y <
+    bounds[x]."""
+
+    if not bounds:
+        raise ValueError,"Invalid bounds"
+    if not (0 <= N < sum(bounds)):
+        raise ValueError,"Invalid input (out of bounds)"
+
+    level = 0
+    active = range(len(bounds))
+    active.sort(key=lambda i: bounds[i])
+    prevLevel = 0
+    for i,index in enumerate(active):
+        level = bounds[index]
+        W = len(active) - i
+        if level is aleph0:
+            H = aleph0
+        else:
+            H = level - prevLevel
+        levelSize = W*H
+        if N<levelSize: # Found the level
+            idelta,delta = getNthPairBounded(N, W, H)
+            return active[i+idelta],prevLevel+delta
+        else:
+            N -= levelSize
+            prevLevel = level
+    else:
+        raise RuntimError,"Unexpected loop completion"
+
+def getNthPairVariableBoundsChecked(N, bounds, GNVP=getNthPairVariableBounds):
+    x,y = GNVP(N,bounds)
+    assert 0 <= x < len(bounds) and 0 <= y < bounds[x]
+    return (x,y)
+
+###
+
+def testPairs():
+    W = 3
+    H = 6
+    a = [['  ' for x in range(10)] for y in range(10)]
+    b = [['  ' for x in range(10)] for y in range(10)]
+    for i in range(min(W*H,40)):
+        x,y = getNthPairBounded(i,W,H)
+        x2,y2 = getNthPairBounded(i,W,H,useDivmod=True)
+        print i,(x,y),(x2,y2)
+        a[y][x] = '%2d'%i
+        b[y2][x2] = '%2d'%i
+
+    print '-- a --'
+    for ln in a[::-1]:
+        if ''.join(ln).strip():
+            print '  '.join(ln)
+    print '-- b --'
+    for ln in b[::-1]:
+        if ''.join(ln).strip():
+            print '  '.join(ln)
+
+def testPairsVB():
+    bounds = [2,2,4,aleph0,5,aleph0]
+    a = [['  ' for x in range(15)] for y in range(15)]
+    b = [['  ' for x in range(15)] for y in range(15)]
+    for i in range(min(sum(bounds),40)):
+        x,y = getNthPairVariableBounds(i, bounds)
+        print i,(x,y)
+        a[y][x] = '%2d'%i
+
+    print '-- a --'
+    for ln in a[::-1]:
+        if ''.join(ln).strip():
+            print '  '.join(ln)
+
+###
+
+# Toggle to use checked versions of enumeration routines.
+if False:
+    getNthPairVariableBounds = getNthPairVariableBoundsChecked
+    getNthPairBounded = getNthPairBoundedChecked
+    getNthNTuple = getNthNTupleChecked
+    getNthTuple = getNthTupleChecked
+
+if __name__ == '__main__':
+    testPairs()
+
+    testPairsVB()
+