mirror of
https://github.com/c64scene-ar/llvm-6502.git
synced 2024-12-23 15:29:51 +00:00
7d9f2b93a3
long test(long x) { return (x & 123124) | 3; }
Currently compiles to:
_test:
orl $3, %edi
movq %rdi, %rax
andq $123127, %rax
ret
This is because instruction and DAG combiners canonicalize
(or (and x, C), D) -> (and (or, D), (C | D))
However, this is only profitable if (C & D) != 0. It gets in the way of the
3-addressification because the input bits are known to be zero.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@97616 91177308-0d34-0410-b5e6-96231b3b80d8
27 lines
790 B
LLVM
27 lines
790 B
LLVM
; RUN: llc < %s -mtriple=i686-apple-darwin | FileCheck -check-prefix=DARWIN %s
|
|
; RUN: opt < %s -O2 | llc -mtriple=x86_64-apple-darwin | FileCheck -check-prefix=DARWIN-OPT %s
|
|
|
|
; The dag combiner should fold together (x&127)|(y&16711680) -> (x|y)&c1
|
|
; in this case.
|
|
|
|
define i32 @test1(i32 %x, i16 %y) {
|
|
%tmp1 = zext i16 %y to i32
|
|
%tmp2 = and i32 %tmp1, 127
|
|
%tmp4 = shl i32 %x, 16
|
|
%tmp5 = and i32 %tmp4, 16711680
|
|
%tmp6 = or i32 %tmp2, %tmp5
|
|
ret i32 %tmp6
|
|
; DARWIN: andl $16711807, %eax
|
|
}
|
|
|
|
; <rdar://problem/7529774> The optimizer shouldn't fold this into (and (or, C), D)
|
|
; if (C & D) == 0
|
|
define i64 @test2(i64 %x) nounwind readnone ssp {
|
|
entry:
|
|
%tmp1 = and i64 %x, 123127
|
|
%tmp2 = or i64 %tmp1, 3
|
|
ret i64 %tmp2
|
|
; DARWIN-OPT: andq $123124
|
|
; DARWIN-OPT-NEXT: leaq 3
|
|
}
|