mirror of
https://github.com/c64scene-ar/llvm-6502.git
synced 2024-12-22 07:32:48 +00:00
fe02c69f84
simplification in fully optimized code. It occurs sporadically in the testsuite, and many times in 403.gcc: the final bitcode has 131 fewer subtractions after this change. The reason that the multiplies are not eliminated is the same reason that instcombine did not catch this: they are used by other instructions (instcombine catches this with a more general transform which in general is only profitable if the operands have only one use). git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@123754 91177308-0d34-0410-b5e6-96231b3b80d8
63 lines
1.2 KiB
LLVM
63 lines
1.2 KiB
LLVM
; RUN: opt < %s -instsimplify -S | FileCheck %s
|
|
|
|
define i32 @factorize(i32 %x, i32 %y) {
|
|
; CHECK: @factorize
|
|
; (X | 1) & (X | 2) -> X | (1 & 2) -> X
|
|
%l = or i32 %x, 1
|
|
%r = or i32 %x, 2
|
|
%z = and i32 %l, %r
|
|
ret i32 %z
|
|
; CHECK: ret i32 %x
|
|
}
|
|
|
|
define i32 @factorize2(i32 %x) {
|
|
; CHECK: @factorize2
|
|
; 3*X - 2*X -> X
|
|
%l = mul i32 3, %x
|
|
%r = mul i32 2, %x
|
|
%z = sub i32 %l, %r
|
|
ret i32 %z
|
|
; CHECK: ret i32 %x
|
|
}
|
|
|
|
define i32 @factorize3(i32 %x, i32 %a, i32 %b) {
|
|
; CHECK: @factorize3
|
|
; (X | (A|B)) & (X | B) -> X | ((A|B) & B) -> X | B
|
|
%aORb = or i32 %a, %b
|
|
%l = or i32 %x, %aORb
|
|
%r = or i32 %x, %b
|
|
%z = and i32 %l, %r
|
|
ret i32 %z
|
|
; CHECK: ret i32 %r
|
|
}
|
|
|
|
define i32 @factorize4(i32 %x, i32 %y) {
|
|
; CHECK: @factorize4
|
|
%sh = shl i32 %y, 1
|
|
%ml = mul i32 %sh, %x
|
|
%mr = mul i32 %x, %y
|
|
%s = sub i32 %ml, %mr
|
|
ret i32 %s
|
|
; CHECK: ret i32 %mr
|
|
}
|
|
|
|
define i32 @factorize5(i32 %x, i32 %y) {
|
|
; CHECK: @factorize5
|
|
%sh = mul i32 %y, 2
|
|
%ml = mul i32 %sh, %x
|
|
%mr = mul i32 %x, %y
|
|
%s = sub i32 %ml, %mr
|
|
ret i32 %s
|
|
; CHECK: ret i32 %mr
|
|
}
|
|
|
|
define i32 @expand(i32 %x) {
|
|
; CHECK: @expand
|
|
; ((X & 1) | 2) & 1 -> ((X & 1) & 1) | (2 & 1) -> (X & 1) | 0 -> X & 1
|
|
%a = and i32 %x, 1
|
|
%b = or i32 %a, 2
|
|
%c = and i32 %b, 1
|
|
ret i32 %c
|
|
; CHECK: ret i32 %a
|
|
}
|