;RUN: opt -S -reassociate < %s | FileCheck %s ; ========================================================================== ; ; Xor reassociation general cases ; ; ========================================================================== ; (x | c1) ^ (x | c2) => (x & c3) ^ c3, where c3 = c1^c2 ; define i32 @xor1(i32 %x) { %or = or i32 %x, 123 %or1 = or i32 %x, 456 %xor = xor i32 %or, %or1 ret i32 %xor ;CHECK-LABEL: @xor1( ;CHECK: %and.ra = and i32 %x, 435 ;CHECK: %xor = xor i32 %and.ra, 435 } ; Test rule : (x & c1) ^ (x & c2) = (x & (c1^c2)) ; Real testing case : (x & 123) ^ y ^ (x & 345) => (x & 435) ^ y define i32 @xor2(i32 %x, i32 %y) { %and = and i32 %x, 123 %xor = xor i32 %and, %y %and1 = and i32 %x, 456 %xor2 = xor i32 %xor, %and1 ret i32 %xor2 ;CHECK-LABEL: @xor2( ;CHECK: %and.ra = and i32 %x, 435 ;CHECK: %xor2 = xor i32 %and.ra, %y } ; Test rule: (x | c1) ^ (x & c2) = (x & c3) ^ c1, where c3 = ~c1 ^ c2 ; c3 = ~c1 ^ c2 define i32 @xor3(i32 %x, i32 %y) { %or = or i32 %x, 123 %xor = xor i32 %or, %y %and = and i32 %x, 456 %xor1 = xor i32 %xor, %and ret i32 %xor1 ;CHECK-LABEL: @xor3( ;CHECK: %and.ra = and i32 %x, -436 ;CHECK: %xor = xor i32 %y, 123 ;CHECK: %xor1 = xor i32 %xor, %and.ra } ; Test rule: (x | c1) ^ c2 = (x & ~c1) ^ (c1 ^ c2) define i32 @xor4(i32 %x, i32 %y) { %and = and i32 %x, -124 %xor = xor i32 %y, 435 %xor1 = xor i32 %xor, %and ret i32 %xor1 ; CHECK-LABEL: @xor4( ; CHECK: %and = and i32 %x, -124 ; CHECK: %xor = xor i32 %y, 435 ; CHECK: %xor1 = xor i32 %xor, %and } ; ========================================================================== ; ; Xor reassociation special cases ; ; ========================================================================== ; Special case1: ; (x | c1) ^ (x & ~c1) = c1 define i32 @xor_special1(i32 %x, i32 %y) { %or = or i32 %x, 123 %xor = xor i32 %or, %y %and = and i32 %x, -124 %xor1 = xor i32 %xor, %and ret i32 %xor1 ; CHECK-LABEL: @xor_special1( ; CHECK: %xor1 = xor i32 %y, 123 ; CHECK: ret i32 %xor1 } ; Special case1: ; (x | c1) ^ (x & c1) = x ^ c1 define i32 @xor_special2(i32 %x, i32 %y) { %or = or i32 %x, 123 %xor = xor i32 %or, %y %and = and i32 %x, 123 %xor1 = xor i32 %xor, %and ret i32 %xor1 ; CHECK-LABEL: @xor_special2( ; CHECK: %xor = xor i32 %y, 123 ; CHECK: %xor1 = xor i32 %xor, %x ; CHECK: ret i32 %xor1 } ; (x | c1) ^ (x | c1) => 0 define i32 @xor_special3(i32 %x) { %or = or i32 %x, 123 %or1 = or i32 %x, 123 %xor = xor i32 %or, %or1 ret i32 %xor ;CHECK-LABEL: @xor_special3( ;CHECK: ret i32 0 } ; (x & c1) ^ (x & c1) => 0 define i32 @xor_special4(i32 %x) { %or = and i32 %x, 123 %or1 = and i32 123, %x %xor = xor i32 %or, %or1 ret i32 %xor ;CHECK-LABEL: @xor_special4( ;CHECK: ret i32 0 } ; ========================================================================== ; ; Xor reassociation curtail code size ; ; ========================================================================== ; (x | c1) ^ (x | c2) => (x & c3) ^ c3 ; is enabled if one of operands has multiple uses ; define i32 @xor_ra_size1(i32 %x) { %or = or i32 %x, 123 %or1 = or i32 %x, 456 %xor = xor i32 %or, %or1 %add = add i32 %xor, %or ret i32 %add ;CHECK-LABEL: @xor_ra_size1( ;CHECK: %xor = xor i32 %and.ra, 435 } ; (x | c1) ^ (x | c2) => (x & c3) ^ c3 ; is disenabled if bothf operands has multiple uses. ; define i32 @xor_ra_size2(i32 %x) { %or = or i32 %x, 123 %or1 = or i32 %x, 456 %xor = xor i32 %or, %or1 %add = add i32 %xor, %or %add2 = add i32 %add, %or1 ret i32 %add2 ;CHECK-LABEL: @xor_ra_size2( ;CHECK: %or1 = or i32 %x, 456 ;CHECK: %xor = xor i32 %or, %or1 } ; ========================================================================== ; ; Xor reassociation bugs ; ; ========================================================================== @xor_bug1_data = external global <{}>, align 4 define void @xor_bug1() { %1 = ptrtoint i32* undef to i64 %2 = xor i64 %1, ptrtoint (<{}>* @xor_bug1_data to i64) %3 = and i64 undef, %2 ret void } ; The bug was that when the compiler optimize "(x | c1)" ^ "(x & c2)", it may ; swap the two xor-subexpressions if they are not in canoninical order; however, ; when optimizer swaps two sub-expressions, if forgot to swap the cached value ; of c1 and c2 accordingly, hence cause the problem. ; define i32 @xor_bug2(i32, i32, i32, i32) { %5 = mul i32 %0, 123 %6 = add i32 %2, 24 %7 = add i32 %1, 8 %8 = and i32 %1, 3456789 %9 = or i32 %8, 4567890 %10 = and i32 %1, 543210987 %11 = or i32 %1, 891034567 %12 = and i32 %2, 255 %13 = xor i32 %9, %10 %14 = xor i32 %11, %13 %15 = xor i32 %5, %14 %16 = and i32 %3, 255 %17 = xor i32 %16, 42 %18 = add i32 %6, %7 %19 = add i32 %18, %12 %20 = add i32 %19, %15 ret i32 %20 ;CHECK-LABEL: @xor_bug2( ;CHECK: xor i32 %5, 891034567 }