Souper says:

; Function: fn1
%0:i32 = var 
%1:i64 = sext %0
%2:i32 = lshr %0, 31:i32
%3:i32 = xor 1:i32, %2
%4:i64 = zext %3
%5:i64 = xor 4842753371:i64, %4
%6:i1 = sle %1, %5
cand %6 1:i1

COMMAND: /home/regehr/souper/build/souper -stp-path=/usr/local/bin/stp reduce_795/foo.bc

LLVM says:

define void @fn1() #0 {
entry:
  %0 = load i32* @b, align 4, !tbaa !1
  %.lobit = lshr i32 %0, 31
  %.lobit.not = xor i32 %.lobit, 1
  %conv15 = zext i32 %.lobit.not to i64
  %xor = xor i64 %conv15, 4842753371
  %conv2 = sext i32 %0 to i64
  %cmp3 = icmp sge i64 %xor, %conv2
  %conv4 = zext i1 %cmp3 to i32
  store i32 %conv4, i32* @a, align 4, !tbaa !1
  ret void
}

COMMAND: /home/regehr/souper/third_party/llvm/Debug/bin/clang -c -w -emit-llvm -O3 reduce_795/foo.c -o reduce_795/foo.bc

C source code:

int a, b;
void fn1() { a = (0 <= b ^ 4842753371) >= b; }

x86-64 from LLVM:

fn1:                                    # @fn1
	movslq	b(%rip), %rax
	movl	%eax, %ecx
	shrl	$31, %ecx
	xorl	$1, %ecx
	movabsq	$4842753371, %rdx       # imm = 0x120A68D5B
	xorq	%rcx, %rdx
	cmpq	%rax, %rdx
	setge	%al
	movzbl	%al, %eax
	movl	%eax, a(%rip)
	retq

COMMAND: /home/regehr/souper/third_party/llvm/Debug/bin/clang -w -O3 reduce_795/foo.c -S -o -

x86-64 from GCC:

fn1:
	movl	$1, a(%rip)
	ret

COMMAND: gcc -w -O3 reduce_795/foo.c -S -o -