mirror of
https://github.com/c64scene-ar/llvm-6502.git
synced 2024-11-11 08:07:22 +00:00
9c64030445
We have to do this in DAGBuilder instead of DAGCombiner, because the exact bit is lost after building.
struct foo { char x[24]; };
long bar(struct foo *a, struct foo *b) { return a-b; }
is now compiled into
movl 4(%esp), %eax
subl 8(%esp), %eax
sarl $3, %eax
imull $-1431655765, %eax, %eax
instead of
movl 4(%esp), %eax
subl 8(%esp), %eax
movl $715827883, %ecx
imull %ecx
movl %edx, %eax
shrl $31, %eax
sarl $2, %edx
addl %eax, %edx
movl %edx, %eax
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@134695 91177308-0d34-0410-b5e6-96231b3b80d8
19 lines
351 B
LLVM
19 lines
351 B
LLVM
; RUN: llc -march=x86 < %s | FileCheck %s
|
|
|
|
define i32 @test1(i32 %x) {
|
|
%div = sdiv exact i32 %x, 25
|
|
ret i32 %div
|
|
; CHECK: test1:
|
|
; CHECK: imull $-1030792151, 4(%esp)
|
|
; CHECK-NEXT: ret
|
|
}
|
|
|
|
define i32 @test2(i32 %x) {
|
|
%div = sdiv exact i32 %x, 24
|
|
ret i32 %div
|
|
; CHECK: test2:
|
|
; CHECK: sarl $3
|
|
; CHECK-NEXT: imull $-1431655765
|
|
; CHECK-NEXT: ret
|
|
}
|