Found the following significant warnings:
  gdfit_binomial.c:31:11: warning: suggest parentheses around comparison in operand of '|' [-Wparentheses]
  gdfit_binomial.c:136:14: warning: suggest parentheses around comparison in operand of '|' [-Wparentheses]
  gdfit_binomial.c:136:45: warning: suggest parentheses around comparison in operand of '|' [-Wparentheses]
  gdfit_cox.c:29:11: warning: suggest parentheses around comparison in operand of '|' [-Wparentheses]
  gdfit_cox.c:131:14: warning: suggest parentheses around comparison in operand of '|' [-Wparentheses]
  gdfit_cox.c:131:45: warning: suggest parentheses around comparison in operand of '|' [-Wparentheses]
  gdfit_gaussian.c:36:11: warning: suggest parentheses around comparison in operand of '|' [-Wparentheses]
  gdfit_gaussian.c:346:14: warning: suggest parentheses around comparison in operand of '|' [-Wparentheses]
  gdfit_gaussian.c:346:45: warning: suggest parentheses around comparison in operand of '|' [-Wparentheses]
  gdfit_poisson.c:31:11: warning: suggest parentheses around comparison in operand of '|' [-Wparentheses]
  gdfit_poisson.c:135:14: warning: suggest parentheses around comparison in operand of '|' [-Wparentheses]
  gdfit_poisson.c:135:45: warning: suggest parentheses around comparison in operand of '|' [-Wparentheses]
  lcdfit_binomial.c:221:14: warning: suggest parentheses around comparison in operand of '|' [-Wparentheses]
  lcdfit_binomial.c:221:45: warning: suggest parentheses around comparison in operand of '|' [-Wparentheses]
  lcdfit_cox.c:240:14: warning: suggest parentheses around comparison in operand of '|' [-Wparentheses]
  lcdfit_cox.c:240:45: warning: suggest parentheses around comparison in operand of '|' [-Wparentheses]
  lcdfit_gaussian.c:193:14: warning: suggest parentheses around comparison in operand of '|' [-Wparentheses]
  lcdfit_gaussian.c:193:45: warning: suggest parentheses around comparison in operand of '|' [-Wparentheses]
  lcdfit_poisson.c:220:14: warning: suggest parentheses around comparison in operand of '|' [-Wparentheses]
  lcdfit_poisson.c:220:45: warning: suggest parentheses around comparison in operand of '|' [-Wparentheses]
See 'd:/Rcompile/CRANpkg/local/3.5/grpreg.Rcheck/00install.out' for details.