Miscompilation at O3

[dtcxzyw]

#include "csmith.h"
uint32_t a;
int16_t c;
void d() {
  for (a = -15; a >= 6; a = safe_add_func_uint16_t_u_u(a, 9))
    ;
  c = safe_lshift_func_int16_t_s_u(safe_lshift_func_uint16_t_u_s(a,14), 0);
}
int main() {
  d();
  printf("%d\n", c);
  return 0;
}

dtcxzyw@dtcxzyw:~/WorkSpace/Projects/compilers/LLVM/llvm-build$ gcc -O0 test.c -fsanitize=undefined -I/usr/include/csmith -w
dtcxzyw@dtcxzyw:~/WorkSpace/Projects/compilers/LLVM/llvm-build$ ./a.out 
-16384
dtcxzyw@dtcxzyw:~/WorkSpace/Projects/compilers/LLVM/llvm-build$ bin/clang -O3 test.c -I/usr/include/csmith -w
dtcxzyw@dtcxzyw:~/WorkSpace/Projects/compilers/LLVM/llvm-build$ ./a.out 
0

llvm version: 2d6ff0c

[dtcxzyw]

Reduced testcase: https://alive2.llvm.org/ce/z/9fExrA

; bin/opt -passes=instcombine test.ll -S
define i16 @src() {
entry:
  br label %for.inc

for.inc:
  %storemerge6 = phi i32 [ -15, %entry ], [ %conv1, %for.inc ]
  %add.i = add nsw i32 %storemerge6, 9
  %conv1 = and i32 %add.i, 65535
  %cmp = icmp ugt i32 %conv1, 5
  br i1 %cmp, label %for.inc, label %for.end

for.end:
  %conv2 = trunc nuw nsw i32 %conv1 to i16
  %cmp3.i = icmp ugt i32 %conv1, 3
  %0 = shl nuw i16 %conv2, 14
  %cond.in.i = select i1 %cmp3.i, i16 %conv2, i16 %0
  ret i16 %cond.in.i
}