1
0
mirror of https://github.com/RPCS3/llvm-mirror.git synced 2024-11-23 03:02:36 +01:00
llvm-mirror/test/CodeGen/PowerPC/hoist-logic.ll
Sanjay Patel 504d614e86 [DAGCombiner] don't hoist logic op if operands have other uses, part 2
The PPC test with 2 extra uses seems clearly better by avoiding this transform. 
With 1 extra use, we also prevent an extra register move (although that might
be an RA problem). The general rule should be to only make a change here if
it is always profitable. The x86 diffs are all neutral.

llvm-svn: 348518
2018-12-06 19:18:56 +00:00

72 lines
1.9 KiB
LLVM

; NOTE: Assertions have been autogenerated by utils/update_llc_test_checks.py
; RUN: llc < %s -verify-machineinstrs -mtriple=powerpc64-unknown-linux-gnu | FileCheck %s
; This is good - eliminate an op by hoisting logic.
define i32 @lshr_or(i32 %x, i32 %y, i32 %z, i32* %p1, i32* %p2) {
; CHECK-LABEL: lshr_or:
; CHECK: # %bb.0:
; CHECK-NEXT: or 3, 3, 4
; CHECK-NEXT: srw 3, 3, 5
; CHECK-NEXT: blr
%xt = lshr i32 %x, %z
%yt = lshr i32 %y, %z
%r = or i32 %xt, %yt
ret i32 %r
}
; This is questionable - hoisting doesn't eliminate anything.
; It might result in an extra register move.
define i32 @lshr_or_multiuse1(i32 %x, i32 %y, i32 %z, i32* %p1, i32* %p2) {
; CHECK-LABEL: lshr_or_multiuse1:
; CHECK: # %bb.0:
; CHECK-NEXT: srw 7, 3, 5
; CHECK-NEXT: srw 3, 4, 5
; CHECK-NEXT: or 3, 7, 3
; CHECK-NEXT: stw 7, 0(6)
; CHECK-NEXT: blr
%xt = lshr i32 %x, %z
%yt = lshr i32 %y, %z
store i32 %xt, i32* %p1
%r = or i32 %xt, %yt
ret i32 %r
}
; This is questionable - hoisting doesn't eliminate anything.
define i32 @lshr_multiuse2(i32 %x, i32 %y, i32 %z, i32* %p1, i32* %p2) {
; CHECK-LABEL: lshr_multiuse2:
; CHECK: # %bb.0:
; CHECK-NEXT: srw 3, 3, 5
; CHECK-NEXT: srw 4, 4, 5
; CHECK-NEXT: or 3, 3, 4
; CHECK-NEXT: stw 4, 0(7)
; CHECK-NEXT: blr
%xt = lshr i32 %x, %z
%yt = lshr i32 %y, %z
store i32 %yt, i32* %p2
%r = or i32 %xt, %yt
ret i32 %r
}
; This is not profitable to hoist. We need an extra shift instruction.
define i32 @lshr_multiuse3(i32 %x, i32 %y, i32 %z, i32* %p1, i32* %p2) {
; CHECK-LABEL: lshr_multiuse3:
; CHECK: # %bb.0:
; CHECK-NEXT: srw 3, 3, 5
; CHECK-NEXT: srw 4, 4, 5
; CHECK-NEXT: stw 3, 0(6)
; CHECK-NEXT: or 3, 3, 4
; CHECK-NEXT: stw 4, 0(7)
; CHECK-NEXT: blr
%xt = lshr i32 %x, %z
%yt = lshr i32 %y, %z
store i32 %xt, i32* %p1
store i32 %yt, i32* %p2
%r = or i32 %xt, %yt
ret i32 %r
}