| ; NOTE: Assertions have been autogenerated by utils/update_llc_test_checks.py |
| ; RUN: llc -mtriple=aarch64-linux-gnu %s -o - | FileCheck %s |
| |
| ; The test cases in this file check following transformation if the right form |
| ; can reduce latency. |
| ; A - (B + C) ==> (A - B) - C |
| |
| ; 32 bit version. |
| define i32 @test1(i32 %a, i32 %b, i32 %c) { |
| ; CHECK-LABEL: test1: |
| ; CHECK: // %bb.0: // %entry |
| ; CHECK-NEXT: add w9, w0, #100 |
| ; CHECK-NEXT: orr w8, w2, #0x80 |
| ; CHECK-NEXT: sub w8, w8, w9 |
| ; CHECK-NEXT: eor w9, w1, w9, lsl #8 |
| ; CHECK-NEXT: sub w8, w8, w9 |
| ; CHECK-NEXT: eor w0, w8, w9, asr #13 |
| ; CHECK-NEXT: ret |
| entry: |
| %c1 = or i32 %c, 128 |
| %a1 = add i32 %a, 100 |
| %shl = shl i32 %a1, 8 |
| %xor = xor i32 %shl, %b |
| %add = add i32 %xor, %a1 |
| %sub = sub i32 %c1, %add |
| %shr = ashr i32 %xor, 13 |
| %xor2 = xor i32 %sub, %shr |
| ret i32 %xor2 |
| } |
| |
| ; 64 bit version. |
| define i64 @test2(i64 %a, i64 %b, i64 %c) { |
| ; CHECK-LABEL: test2: |
| ; CHECK: // %bb.0: // %entry |
| ; CHECK-NEXT: add x9, x0, #100 |
| ; CHECK-NEXT: orr x8, x2, #0x80 |
| ; CHECK-NEXT: sub x8, x8, x9 |
| ; CHECK-NEXT: eor x9, x1, x9, lsl #8 |
| ; CHECK-NEXT: sub x8, x8, x9 |
| ; CHECK-NEXT: eor x0, x8, x9, asr #13 |
| ; CHECK-NEXT: ret |
| entry: |
| %c1 = or i64 %c, 128 |
| %a1 = add i64 %a, 100 |
| %shl = shl i64 %a1, 8 |
| %xor = xor i64 %shl, %b |
| %add = add i64 %xor, %a1 |
| %sub = sub i64 %c1, %add |
| %shr = ashr i64 %xor, 13 |
| %xor2 = xor i64 %sub, %shr |
| ret i64 %xor2 |
| } |
| |
| ; Negative test. The right form can't reduce latency. |
| define i32 @test3(i32 %a, i32 %b, i32 %c) { |
| ; CHECK-LABEL: test3: |
| ; CHECK: // %bb.0: // %entry |
| ; CHECK-NEXT: add w9, w0, #100 |
| ; CHECK-NEXT: orr w8, w2, #0x80 |
| ; CHECK-NEXT: add w8, w8, w9 |
| ; CHECK-NEXT: eor w9, w1, w9, lsl #8 |
| ; CHECK-NEXT: sub w8, w9, w8 |
| ; CHECK-NEXT: eor w0, w8, w9, asr #13 |
| ; CHECK-NEXT: ret |
| entry: |
| %c1 = or i32 %c, 128 |
| %a1 = add i32 %a, 100 |
| %shl = shl i32 %a1, 8 |
| %xor = xor i32 %shl, %b |
| %add = add i32 %c1, %a1 |
| %sub = sub i32 %xor, %add |
| %shr = ashr i32 %xor, 13 |
| %xor2 = xor i32 %sub, %shr |
| ret i32 %xor2 |
| } |
| |