Souper says:

; Function: fn1
%0:i32 = var 
%1:i32 = srem 1:i32, %0
%2:i32 = and 32768:i32, %1
%3:i1 = ne 0:i32, %2
cand %3 0:i1

COMMAND: /home/regehr/souper/build/souper -stp-path=/usr/local/bin/stp reduce_495/foo.bc

LLVM says:

define void @fn1() #0 {
entry:
  %0 = load i32* @a, align 4, !tbaa !1
  %rem = srem i32 1, %0
  %conv = trunc i32 %rem to i16
  store i16 %conv, i16* @b, align 2, !tbaa !5
  %sext.mask = and i32 %rem, 32768
  %cmp = icmp ne i32 %sext.mask, 0
  %1 = lshr i32 %rem, 15
  %sext.lobit = and i32 %1, 1
  %conv2. = select i1 %cmp, i32 %sext.lobit, i32 0
  store i32 %conv2., i32* @c, align 4, !tbaa !1
  ret void
}

COMMAND: /home/regehr/souper/third_party/llvm/Debug/bin/clang -c -w -emit-llvm -O3 reduce_495/foo.c -o reduce_495/foo.bc

C source code:

int a, c;
short b;
void fn1() {
  c = 1 % a;
  b = c;
  c = b < 0 ?: 0;
}

x86-64 from LLVM:

fn1:                                    # @fn1
	movl	$1, %eax
	xorl	%edx, %edx
	idivl	a(%rip)
	movw	%dx, b(%rip)
	movl	%edx, %eax
	andl	$32768, %eax            # imm = 0x8000
	shrl	$15, %eax
	shrl	$15, %edx
	andl	$1, %edx
	testl	%eax, %eax
	cmovel	%eax, %edx
	movl	%edx, c(%rip)
	retq

COMMAND: /home/regehr/souper/third_party/llvm/Debug/bin/clang -w -O3 reduce_495/foo.c -S -o -

x86-64 from GCC:

fn1:
	movl	$1, %eax
	cltd
	idivl	a(%rip)
	movswl	%dx, %eax
	movw	%dx, b(%rip)
	shrl	$31, %eax
	movl	%eax, c(%rip)
	ret

COMMAND: gcc -w -O3 reduce_495/foo.c -S -o -