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-rw-r--r--code/tools/lcc/src/simp.c587
1 files changed, 587 insertions, 0 deletions
diff --git a/code/tools/lcc/src/simp.c b/code/tools/lcc/src/simp.c
new file mode 100644
index 0000000..ea26ab6
--- /dev/null
+++ b/code/tools/lcc/src/simp.c
@@ -0,0 +1,587 @@
+#include "c.h"
+#include <float.h>
+
+
+#define foldcnst(TYPE,VAR,OP) \
+ if (l->op == CNST+TYPE && r->op == CNST+TYPE) \
+ return cnsttree(ty, l->u.v.VAR OP r->u.v.VAR)
+#define commute(L,R) \
+ if (generic(R->op) == CNST && generic(L->op) != CNST) \
+ do { Tree t = L; L = R; R = t; } while(0)
+#define xfoldcnst(TYPE,VAR,OP,FUNC)\
+ if (l->op == CNST+TYPE && r->op == CNST+TYPE\
+ && FUNC(l->u.v.VAR,r->u.v.VAR,\
+ ty->u.sym->u.limits.min.VAR,\
+ ty->u.sym->u.limits.max.VAR, needconst)) \
+ return cnsttree(ty, l->u.v.VAR OP r->u.v.VAR)
+#define xcvtcnst(FTYPE,SRC,DST,VAR,EXPR) \
+ if (l->op == CNST+FTYPE) do {\
+ if (!explicitCast\
+ && ((SRC) < DST->u.sym->u.limits.min.VAR || (SRC) > DST->u.sym->u.limits.max.VAR))\
+ warning("overflow in converting constant expression from `%t' to `%t'\n", l->type, DST);\
+ if (needconst\
+ || !((SRC) < DST->u.sym->u.limits.min.VAR || (SRC) > DST->u.sym->u.limits.max.VAR))\
+ return cnsttree(ty, (EXPR)); } while(0)
+#define identity(X,Y,TYPE,VAR,VAL) \
+ if (X->op == CNST+TYPE && X->u.v.VAR == VAL) return Y
+#define zerofield(OP,TYPE,VAR) \
+ if (l->op == FIELD \
+ && r->op == CNST+TYPE && r->u.v.VAR == 0)\
+ return eqtree(OP, bittree(BAND, l->kids[0],\
+ cnsttree(unsignedtype, \
+ (unsigned long)fieldmask(l->u.field)<<fieldright(l->u.field))), r)
+#define cfoldcnst(TYPE,VAR,OP) \
+ if (l->op == CNST+TYPE && r->op == CNST+TYPE) \
+ return cnsttree(inttype, (long)(l->u.v.VAR OP r->u.v.VAR))
+#define foldaddp(L,R,RTYPE,VAR) \
+ if (L->op == CNST+P && R->op == CNST+RTYPE) { \
+ Tree e = tree(CNST+P, ty, NULL, NULL);\
+ e->u.v.p = (char *)L->u.v.p + R->u.v.VAR;\
+ return e; }
+#define ufoldcnst(TYPE,EXP) if (l->op == CNST+TYPE) return EXP
+#define sfoldcnst(OP) \
+ if (l->op == CNST+U && r->op == CNST+I \
+ && r->u.v.i >= 0 && r->u.v.i < 8*l->type->size) \
+ return cnsttree(ty, (unsigned long)(l->u.v.u OP r->u.v.i))
+#define geu(L,R,V) \
+ if (R->op == CNST+U && R->u.v.u == 0) do { \
+ warning("result of unsigned comparison is constant\n"); \
+ return tree(RIGHT, inttype, root(L), cnsttree(inttype, (long)(V))); } while(0)
+#define idempotent(OP) if (l->op == OP) return l->kids[0]
+
+int needconst;
+int explicitCast;
+static int addi(long x, long y, long min, long max, int needconst) {
+ int cond = x == 0 || y == 0
+ || (x < 0 && y < 0 && x >= min - y)
+ || (x < 0 && y > 0)
+ || (x > 0 && y < 0)
+ || (x > 0 && y > 0 && x <= max - y);
+ if (!cond && needconst) {
+ warning("overflow in constant expression\n");
+ cond = 1;
+ }
+ return cond;
+
+
+}
+
+static int addd(double x, double y, double min, double max, int needconst) {
+ int cond = x == 0 || y == 0
+ || (x < 0 && y < 0 && x >= min - y)
+ || (x < 0 && y > 0)
+ || (x > 0 && y < 0)
+ || (x > 0 && y > 0 && x <= max - y);
+ if (!cond && needconst) {
+ warning("overflow in constant expression\n");
+ cond = 1;
+ }
+ return cond;
+
+
+}
+
+static Tree addrtree(Tree e, long n, Type ty) {
+ Symbol p = e->u.sym, q;
+
+ if (p->scope == GLOBAL
+ || p->sclass == STATIC || p->sclass == EXTERN)
+ NEW0(q, PERM);
+ else
+ NEW0(q, FUNC);
+ q->name = stringd(genlabel(1));
+ q->sclass = p->sclass;
+ q->scope = p->scope;
+ assert(isptr(ty) || isarray(ty));
+ q->type = isptr(ty) ? ty->type : ty;
+ q->temporary = p->temporary;
+ q->generated = p->generated;
+ q->addressed = p->addressed;
+ q->computed = 1;
+ q->defined = 1;
+ q->ref = 1;
+ if (p->scope == GLOBAL
+ || p->sclass == STATIC || p->sclass == EXTERN) {
+ if (p->sclass == AUTO)
+ q->sclass = STATIC;
+ (*IR->address)(q, p, n);
+ } else {
+ Code cp;
+ addlocal(p);
+ cp = code(Address);
+ cp->u.addr.sym = q;
+ cp->u.addr.base = p;
+ cp->u.addr.offset = n;
+ }
+ e = tree(e->op, ty, NULL, NULL);
+ e->u.sym = q;
+ return e;
+}
+
+/* div[id] - return 1 if min <= x/y <= max, 0 otherwise */
+static int divi(long x, long y, long min, long max, int needconst) {
+ int cond = y != 0 && !(x == min && y == -1);
+ if (!cond && needconst) {
+ warning("overflow in constant expression\n");
+ cond = 1;
+ }
+ return cond;
+
+
+}
+
+static int divd(double x, double y, double min, double max, int needconst) {
+ int cond;
+
+ if (x < 0) x = -x;
+ if (y < 0) y = -y;
+ cond = y != 0 && !(y < 1 && x > max*y);
+ if (!cond && needconst) {
+ warning("overflow in constant expression\n");
+ cond = 1;
+ }
+ return cond;
+
+}
+
+/* mul[id] - return 1 if min <= x*y <= max, 0 otherwise */
+static int muli(long x, long y, long min, long max, int needconst) {
+ int cond = (x > -1 && x <= 1) || (y > -1 && y <= 1)
+ || (x < 0 && y < 0 && -x <= max/-y)
+ || (x < 0 && y > 0 && x >= min/y)
+ || (x > 0 && y < 0 && y >= min/x)
+ || (x > 0 && y > 0 && x <= max/y);
+ if (!cond && needconst) {
+ warning("overflow in constant expression\n");
+ cond = 1;
+ }
+ return cond;
+
+
+}
+
+static int muld(double x, double y, double min, double max, int needconst) {
+ int cond = (x >= -1 && x <= 1) || (y >= -1 && y <= 1)
+ || (x < 0 && y < 0 && -x <= max/-y)
+ || (x < 0 && y > 0 && x >= min/y)
+ || (x > 0 && y < 0 && y >= min/x)
+ || (x > 0 && y > 0 && x <= max/y);
+ if (!cond && needconst) {
+ warning("overflow in constant expression\n");
+ cond = 1;
+ }
+ return cond;
+
+
+}
+/* sub[id] - return 1 if min <= x-y <= max, 0 otherwise */
+static int subi(long x, long y, long min, long max, int needconst) {
+ return addi(x, -y, min, max, needconst);
+}
+
+static int subd(double x, double y, double min, double max, int needconst) {
+ return addd(x, -y, min, max, needconst);
+}
+Tree constexpr(int tok) {
+ Tree p;
+
+ needconst++;
+ p = expr1(tok);
+ needconst--;
+ return p;
+}
+
+int intexpr(int tok, int n) {
+ Tree p = constexpr(tok);
+
+ needconst++;
+ if (p->op == CNST+I || p->op == CNST+U)
+ n = cast(p, inttype)->u.v.i;
+ else
+ error("integer expression must be constant\n");
+ needconst--;
+ return n;
+}
+Tree simplify(int op, Type ty, Tree l, Tree r) {
+ int n;
+
+ if (optype(op) == 0)
+ op = mkop(op, ty);
+ switch (op) {
+ case ADD+U:
+ foldcnst(U,u,+);
+ commute(r,l);
+ identity(r,l,U,u,0);
+ break;
+ case ADD+I:
+ xfoldcnst(I,i,+,addi);
+ commute(r,l);
+ identity(r,l,I,i,0);
+ break;
+ case CVI+I:
+ xcvtcnst(I,l->u.v.i,ty,i,(long)extend(l->u.v.i,ty));
+ break;
+ case CVU+I:
+ if (l->op == CNST+U) {
+ if (!explicitCast && l->u.v.u > ty->u.sym->u.limits.max.i)
+ warning("overflow in converting constant expression from `%t' to `%t'\n", l->type, ty);
+ if (needconst || !(l->u.v.u > ty->u.sym->u.limits.max.i))
+ return cnsttree(ty, (long)extend(l->u.v.u,ty));
+ }
+ break;
+ case CVP+U:
+ xcvtcnst(P,(unsigned long)l->u.v.p,ty,u,(unsigned long)l->u.v.p);
+ break;
+ case CVU+P:
+ xcvtcnst(U,(void*)l->u.v.u,ty,p,(void*)l->u.v.u);
+ break;
+ case CVP+P:
+ xcvtcnst(P,l->u.v.p,ty,p,l->u.v.p);
+ break;
+ case CVI+U:
+ xcvtcnst(I,l->u.v.i,ty,u,((unsigned long)l->u.v.i)&ones(8*ty->size));
+ break;
+ case CVU+U:
+ xcvtcnst(U,l->u.v.u,ty,u,l->u.v.u&ones(8*ty->size));
+ break;
+
+ case CVI+F:
+ xcvtcnst(I,l->u.v.i,ty,d,(double)l->u.v.i);
+ case CVU+F:
+ xcvtcnst(U,l->u.v.u,ty,d,(double)l->u.v.u);
+ break;
+ case CVF+I:
+ xcvtcnst(F,l->u.v.d,ty,i,(long)l->u.v.d);
+ break;
+ case CVF+F: {
+ float d = 0.0f;
+ if (l->op == CNST+F) {
+ if (l->u.v.d < ty->u.sym->u.limits.min.d)
+ d = ty->u.sym->u.limits.min.d;
+ else if (l->u.v.d > ty->u.sym->u.limits.max.d)
+ d = ty->u.sym->u.limits.max.d;
+ else
+ d = l->u.v.d;
+ }
+ xcvtcnst(F,l->u.v.d,ty,d,(double)d);
+ break;
+ }
+ case BAND+U:
+ foldcnst(U,u,&);
+ commute(r,l);
+ identity(r,l,U,u,ones(8*ty->size));
+ if (r->op == CNST+U && r->u.v.u == 0)
+ return tree(RIGHT, ty, root(l), cnsttree(ty, 0UL));
+ break;
+ case BAND+I:
+ foldcnst(I,i,&);
+ commute(r,l);
+ identity(r,l,I,i,ones(8*ty->size));
+ if (r->op == CNST+I && r->u.v.u == 0)
+ return tree(RIGHT, ty, root(l), cnsttree(ty, 0L));
+ break;
+
+ case MUL+U:
+ commute(l,r);
+ if (l->op == CNST+U && (n = ispow2(l->u.v.u)) != 0)
+ return simplify(LSH, ty, r, cnsttree(inttype, (long)n));
+ foldcnst(U,u,*);
+ identity(r,l,U,u,1);
+ break;
+ case NE+I:
+ cfoldcnst(I,i,!=);
+ commute(r,l);
+ zerofield(NE,I,i);
+ break;
+
+ case EQ+I:
+ cfoldcnst(I,i,==);
+ commute(r,l);
+ zerofield(EQ,I,i);
+ break;
+ case ADD+P:
+ foldaddp(l,r,I,i);
+ foldaddp(l,r,U,u);
+ foldaddp(r,l,I,i);
+ foldaddp(r,l,U,u);
+ commute(r,l);
+ identity(r,retype(l,ty),I,i,0);
+ identity(r,retype(l,ty),U,u,0);
+ if (isaddrop(l->op)
+ && ((r->op == CNST+I && r->u.v.i <= longtype->u.sym->u.limits.max.i
+ && r->u.v.i >= longtype->u.sym->u.limits.min.i)
+ || (r->op == CNST+U && r->u.v.u <= longtype->u.sym->u.limits.max.i)))
+ return addrtree(l, cast(r, longtype)->u.v.i, ty);
+ if (l->op == ADD+P && isaddrop(l->kids[1]->op)
+ && ((r->op == CNST+I && r->u.v.i <= longtype->u.sym->u.limits.max.i
+ && r->u.v.i >= longtype->u.sym->u.limits.min.i)
+ || (r->op == CNST+U && r->u.v.u <= longtype->u.sym->u.limits.max.i)))
+ return simplify(ADD+P, ty, l->kids[0],
+ addrtree(l->kids[1], cast(r, longtype)->u.v.i, ty));
+ if ((l->op == ADD+I || l->op == SUB+I)
+ && l->kids[1]->op == CNST+I && isaddrop(r->op))
+ return simplify(ADD+P, ty, l->kids[0],
+ simplify(generic(l->op)+P, ty, r, l->kids[1]));
+ if (l->op == ADD+P && generic(l->kids[1]->op) == CNST
+ && generic(r->op) == CNST)
+ return simplify(ADD+P, ty, l->kids[0],
+ simplify(ADD, l->kids[1]->type, l->kids[1], r));
+ if (l->op == ADD+I && generic(l->kids[1]->op) == CNST
+ && r->op == ADD+P && generic(r->kids[1]->op) == CNST)
+ return simplify(ADD+P, ty, l->kids[0],
+ simplify(ADD+P, ty, r->kids[0],
+ simplify(ADD, r->kids[1]->type, l->kids[1], r->kids[1])));
+ if (l->op == RIGHT && l->kids[1])
+ return tree(RIGHT, ty, l->kids[0],
+ simplify(ADD+P, ty, l->kids[1], r));
+ else if (l->op == RIGHT && l->kids[0])
+ return tree(RIGHT, ty,
+ simplify(ADD+P, ty, l->kids[0], r), NULL);
+ break;
+
+ case ADD+F:
+ xfoldcnst(F,d,+,addd);
+ commute(r,l);
+ break;
+ case AND+I:
+ op = AND;
+ ufoldcnst(I,l->u.v.i ? cond(r) : l); /* 0&&r => 0, 1&&r => r */
+ break;
+ case OR+I:
+ op = OR;
+ /* 0||r => r, 1||r => 1 */
+ ufoldcnst(I,l->u.v.i ? cnsttree(ty, 1L) : cond(r));
+ break;
+ case BCOM+I:
+ ufoldcnst(I,cnsttree(ty, (long)extend((~l->u.v.i)&ones(8*ty->size), ty)));
+ idempotent(BCOM+U);
+ break;
+ case BCOM+U:
+ ufoldcnst(U,cnsttree(ty, (unsigned long)((~l->u.v.u)&ones(8*ty->size))));
+ idempotent(BCOM+U);
+ break;
+ case BOR+U:
+ foldcnst(U,u,|);
+ commute(r,l);
+ identity(r,l,U,u,0);
+ break;
+ case BOR+I:
+ foldcnst(I,i,|);
+ commute(r,l);
+ identity(r,l,I,i,0);
+ break;
+ case BXOR+U:
+ foldcnst(U,u,^);
+ commute(r,l);
+ identity(r,l,U,u,0);
+ break;
+ case BXOR+I:
+ foldcnst(I,i,^);
+ commute(r,l);
+ identity(r,l,I,i,0);
+ break;
+ case DIV+F:
+ xfoldcnst(F,d,/,divd);
+ break;
+ case DIV+I:
+ identity(r,l,I,i,1);
+ if ((r->op == CNST+I && r->u.v.i == 0)
+ || (l->op == CNST+I && l->u.v.i == ty->u.sym->u.limits.min.i
+ && r->op == CNST+I && r->u.v.i == -1))
+ break;
+ xfoldcnst(I,i,/,divi);
+ break;
+ case DIV+U:
+ identity(r,l,U,u,1);
+ if (r->op == CNST+U && r->u.v.u == 0)
+ break;
+ if (r->op == CNST+U && (n = ispow2(r->u.v.u)) != 0)
+ return simplify(RSH, ty, l, cnsttree(inttype, (long)n));
+ foldcnst(U,u,/);
+ break;
+ case EQ+F:
+ cfoldcnst(F,d,==);
+ commute(r,l);
+ break;
+ case EQ+U:
+ cfoldcnst(U,u,==);
+ commute(r,l);
+ zerofield(EQ,U,u);
+ break;
+ case GE+F: cfoldcnst(F,d,>=); break;
+ case GE+I: cfoldcnst(I,i,>=); break;
+ case GE+U:
+ geu(l,r,1); /* l >= 0 => (l,1) */
+ cfoldcnst(U,u,>=);
+ if (l->op == CNST+U && l->u.v.u == 0) /* 0 >= r => r == 0 */
+ return eqtree(EQ, r, l);
+ break;
+ case GT+F: cfoldcnst(F,d, >); break;
+ case GT+I: cfoldcnst(I,i, >); break;
+ case GT+U:
+ geu(r,l,0); /* 0 > r => (r,0) */
+ cfoldcnst(U,u, >);
+ if (r->op == CNST+U && r->u.v.u == 0) /* l > 0 => l != 0 */
+ return eqtree(NE, l, r);
+ break;
+ case LE+F: cfoldcnst(F,d,<=); break;
+ case LE+I: cfoldcnst(I,i,<=); break;
+ case LE+U:
+ geu(r,l,1); /* 0 <= r => (r,1) */
+ cfoldcnst(U,u,<=);
+ if (r->op == CNST+U && r->u.v.u == 0) /* l <= 0 => l == 0 */
+ return eqtree(EQ, l, r);
+ break;
+ case LSH+I:
+ identity(r,l,I,i,0);
+ if (l->op == CNST+I && r->op == CNST+I
+ && r->u.v.i >= 0 && r->u.v.i < 8*l->type->size
+ && muli(l->u.v.i, 1<<r->u.v.i, ty->u.sym->u.limits.min.i, ty->u.sym->u.limits.max.i, needconst))
+ return cnsttree(ty, (long)(l->u.v.i<<r->u.v.i));
+ if (r->op == CNST+I && (r->u.v.i >= 8*ty->size || r->u.v.i < 0)) {
+ warning("shifting an `%t' by %d bits is undefined\n", ty, r->u.v.i);
+ break;
+ }
+
+ break;
+ case LSH+U:
+ identity(r,l,I,i,0);
+ sfoldcnst(<<);
+ if (r->op == CNST+I && (r->u.v.i >= 8*ty->size || r->u.v.i < 0)) {
+ warning("shifting an `%t' by %d bits is undefined\n", ty, r->u.v.i);
+ break;
+ }
+
+ break;
+
+ case LT+F: cfoldcnst(F,d, <); break;
+ case LT+I: cfoldcnst(I,i, <); break;
+ case LT+U:
+ geu(l,r,0); /* l < 0 => (l,0) */
+ cfoldcnst(U,u, <);
+ if (l->op == CNST+U && l->u.v.u == 0) /* 0 < r => r != 0 */
+ return eqtree(NE, r, l);
+ break;
+ case MOD+I:
+ if (r->op == CNST+I && r->u.v.i == 1) /* l%1 => (l,0) */
+ return tree(RIGHT, ty, root(l), cnsttree(ty, 0L));
+ if ((r->op == CNST+I && r->u.v.i == 0)
+ || (l->op == CNST+I && l->u.v.i == ty->u.sym->u.limits.min.i
+ && r->op == CNST+I && r->u.v.i == -1))
+ break;
+ xfoldcnst(I,i,%,divi);
+ break;
+ case MOD+U:
+ if (r->op == CNST+U && ispow2(r->u.v.u)) /* l%2^n => l&(2^n-1) */
+ return bittree(BAND, l, cnsttree(ty, r->u.v.u - 1));
+ if (r->op == CNST+U && r->u.v.u == 0)
+ break;
+ foldcnst(U,u,%);
+ break;
+ case MUL+F:
+ xfoldcnst(F,d,*,muld);
+ commute(l,r);
+ break;
+ case MUL+I:
+ commute(l,r);
+ xfoldcnst(I,i,*,muli);
+ if (l->op == CNST+I && r->op == ADD+I && r->kids[1]->op == CNST+I)
+ /* c1*(x + c2) => c1*x + c1*c2 */
+ return simplify(ADD, ty, simplify(MUL, ty, l, r->kids[0]),
+ simplify(MUL, ty, l, r->kids[1]));
+ if (l->op == CNST+I && r->op == SUB+I && r->kids[1]->op == CNST+I)
+ /* c1*(x - c2) => c1*x - c1*c2 */
+ return simplify(SUB, ty, simplify(MUL, ty, l, r->kids[0]),
+ simplify(MUL, ty, l, r->kids[1]));
+ if (l->op == CNST+I && l->u.v.i > 0 && (n = ispow2(l->u.v.i)) != 0)
+ /* 2^n * r => r<<n */
+ return simplify(LSH, ty, r, cnsttree(inttype, (long)n));
+ identity(r,l,I,i,1);
+ break;
+ case NE+F:
+ cfoldcnst(F,d,!=);
+ commute(r,l);
+ break;
+ case NE+U:
+ cfoldcnst(U,u,!=);
+ commute(r,l);
+ zerofield(NE,U,u);
+ break;
+ case NEG+F:
+ ufoldcnst(F,cnsttree(ty, -l->u.v.d));
+ idempotent(NEG+F);
+ break;
+ case NEG+I:
+ if (l->op == CNST+I) {
+ if (needconst && l->u.v.i == ty->u.sym->u.limits.min.i)
+ warning("overflow in constant expression\n");
+ if (needconst || l->u.v.i != ty->u.sym->u.limits.min.i)
+ return cnsttree(ty, -l->u.v.i);
+ }
+ idempotent(NEG+I);
+ break;
+ case NOT+I:
+ op = NOT;
+ ufoldcnst(I,cnsttree(ty, !l->u.v.i));
+ break;
+ case RSH+I:
+ identity(r,l,I,i,0);
+ if (l->op == CNST+I && r->op == CNST+I
+ && r->u.v.i >= 0 && r->u.v.i < 8*l->type->size) {
+ long n = l->u.v.i>>r->u.v.i;
+ if (l->u.v.i < 0)
+ n |= ~0UL<<(8*l->type->size - r->u.v.i);
+ return cnsttree(ty, n);
+ }
+ if (r->op == CNST+I && (r->u.v.i >= 8*ty->size || r->u.v.i < 0)) {
+ warning("shifting an `%t' by %d bits is undefined\n", ty, r->u.v.i);
+ break;
+ }
+
+ break;
+ case RSH+U:
+ identity(r,l,I,i,0);
+ sfoldcnst(>>);
+ if (r->op == CNST+I && (r->u.v.i >= 8*ty->size || r->u.v.i < 0)) {
+ warning("shifting an `%t' by %d bits is undefined\n", ty, r->u.v.i);
+ break;
+ }
+
+ break;
+ case SUB+F:
+ xfoldcnst(F,d,-,subd);
+ break;
+ case SUB+I:
+ xfoldcnst(I,i,-,subi);
+ identity(r,l,I,i,0);
+ break;
+ case SUB+U:
+ foldcnst(U,u,-);
+ identity(r,l,U,u,0);
+ break;
+ case SUB+P:
+ if (l->op == CNST+P && r->op == CNST+P)
+ return cnsttree(ty, (long)((char *)l->u.v.p - (char *)r->u.v.p));
+ if (r->op == CNST+I || r->op == CNST+U)
+ return simplify(ADD, ty, l,
+ cnsttree(inttype, r->op == CNST+I ? -r->u.v.i : -(long)r->u.v.u));
+ if (isaddrop(l->op) && r->op == ADD+I && r->kids[1]->op == CNST+I)
+ /* l - (x + c) => l-c - x */
+ return simplify(SUB, ty,
+ simplify(SUB, ty, l, r->kids[1]), r->kids[0]);
+ break;
+ default:assert(0);
+ }
+ return tree(op, ty, l, r);
+}
+/* ispow2 - if u > 1 && u == 2^n, return n, otherwise return 0 */
+int ispow2(unsigned long u) {
+ int n;
+
+ if (u > 1 && (u&(u-1)) == 0)
+ for (n = 0; u; u >>= 1, n++)
+ if (u&1)
+ return n;
+ return 0;
+}
+
generated by cgit v1.2.3 (git 2.25.1) at 2024-04-18 04:38:12 +0000