Souper says:
; Function: fn1
%0:i32 = var
%1:i32 = srem 1:i32, %0
%2:i1 = ult 1:i32, %1
cand %2 0:i1
COMMAND: /home/regehr/souper/build/souper -stp-path=/usr/local/bin/stp reduce_448/foo.bc
LLVM says:
define void @fn1() #0 {
entry:
%0 = load i32* @a, align 4, !tbaa !1
%rem = srem i32 1, %0
store i32 %rem, i32* @c, align 4, !tbaa !1
%cmp = icmp ugt i32 %rem, 1
%conv = zext i1 %cmp to i32
store i32 %conv, i32* @b, align 4, !tbaa !1
ret void
}
COMMAND: /home/regehr/souper/third_party/llvm/Debug/bin/clang -c -w -emit-llvm -O3 reduce_448/foo.c -o reduce_448/foo.bc
C source code:
int a, b, c;
void fn1() {
c = 1 % a;
b = 1 < c;
}
x86-64 from LLVM:
fn1: # @fn1
movl $1, %eax
xorl %edx, %edx
idivl a(%rip)
cmpl $1, %edx
movl %edx, c(%rip)
seta %al
movzbl %al, %eax
movl %eax, b(%rip)
retq
COMMAND: /home/regehr/souper/third_party/llvm/Debug/bin/clang -w -O3 reduce_448/foo.c -S -o -
x86-64 from GCC:
fn1:
movl $1, %eax
cltd
idivl a(%rip)
xorl %eax, %eax
cmpl $1, %edx
movl %edx, c(%rip)
setg %al
movl %eax, b(%rip)
ret
COMMAND: gcc -w -O3 reduce_448/foo.c -S -o -