Souper says:
; Function: fn1
%0:i32 = var
%1:i1 = slt %0, 1:i32
%2:i32 = zext %1
%3:i1 = eq %0, %2
cand %3 0:i1
COMMAND: /home/regehr/souper/build/souper -stp-path=/usr/local/bin/stp reduce_138/foo.bc
LLVM says:
define void @fn1() #0 {
entry:
%0 = load i32* @a, align 4, !tbaa !1
%cmp = icmp slt i32 %0, 1
%conv = zext i1 %cmp to i32
%cmp1 = icmp eq i32 %conv, %0
%conv2 = zext i1 %cmp1 to i32
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_138/foo.c -o reduce_138/foo.bc
C source code:
int a, c;
static int *b = &a;
void fn1() {
int d = *b;
c = 0 >= a == d;
}
x86-64 from LLVM:
fn1: # @fn1
movl a(%rip), %eax
testl %eax, %eax
setle %cl
movzbl %cl, %ecx
cmpl %eax, %ecx
sete %al
movzbl %al, %eax
movl %eax, c(%rip)
retq
COMMAND: /home/regehr/souper/third_party/llvm/Debug/bin/clang -w -O3 reduce_138/foo.c -S -o -
x86-64 from GCC:
fn1:
movl a(%rip), %eax
xorl %edx, %edx
testl %eax, %eax
setle %dl
cmpl %eax, %edx
sete %al
movzbl %al, %eax
movl %eax, c(%rip)
ret
COMMAND: gcc -w -O3 reduce_138/foo.c -S -o -