[llvm] r253024 - [AArch64] Check the expansion of BITREVERSE in regression test

[James Molloy via llvm-commits]

Author: jamesm
Date: Fri Nov 13 04:05:31 2015
New Revision: 253024

URL: http://llvm.org/viewvc/llvm-project?rev=253024&view=rev
Log:
[AArch64] Check the expansion of BITREVERSE in regression test

Something I missed from Hal's review, rightly pointed out by Ben Kramer - we should make sure the expansion is properly checked as it can be easy for bugs to creep in.

I've checked the scalar i8 expansion here and the vector i8 expansion in a previous commit.

Modified:
    llvm/trunk/test/CodeGen/AArch64/bitreverse.ll

Modified: llvm/trunk/test/CodeGen/AArch64/bitreverse.ll
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/CodeGen/AArch64/bitreverse.ll?rev=253024&r1=253023&r2=253024&view=diff
==============================================================================
--- llvm/trunk/test/CodeGen/AArch64/bitreverse.ll (original)
+++ llvm/trunk/test/CodeGen/AArch64/bitreverse.ll Fri Nov 13 04:05:31 2015
@@ -14,10 +14,29 @@ define <2 x i16> @f(<2 x i16> %a) {
 
 declare i8 @llvm.bitreverse.i8(i8) readnone
 
+; Unfortunately some of the shift-and-inserts become BFIs, and some do not :(
 define i8 @g(i8 %a) {
 ; CHECK-LABEL: g:
-; CHECK: lsl
-; CHECK: and
+; CHECK-DAG: lsr [[S5:w.*]], w0, #5
+; CHECK-DAG: lsr [[S4:w.*]], w0, #4
+; CHECK-DAG: lsr [[S3:w.*]], w0, #3
+; CHECK-DAG: lsr [[S2:w.*]], w0, #2
+; CHECK-DAG: lsl [[L1:w.*]], w0, #29
+; CHECK-DAG: lsl [[L2:w.*]], w0, #19
+; CHECK-DAG: lsl [[L3:w.*]], w0, #17
+
+; CHECK-DAG: and [[T1:w.*]], [[L1]], #0x40000000
+; CHECK-DAG: bfi [[T1]], w0, #31, #1
+; CHECK-DAG: bfi [[T1]], [[S2]], #29, #1
+; CHECK-DAG: bfi [[T1]], [[S3]], #28, #1
+; CHECK-DAG: bfi [[T1]], [[S4]], #27, #1
+; CHECK-DAG: bfi [[T1]], [[S5]], #26, #1
+; CHECK-DAG: and [[T2:w.*]], [[L2]], #0x2000000
+; CHECK-DAG: and [[T3:w.*]], [[L3]], #0x1000000
+; CHECK-DAG: orr [[T4:w.*]], [[T1]], [[T2]]
+; CHECK-DAG: orr [[T5:w.*]], [[T4]], [[T3]]
+; CHECK:     lsr w0, [[T5]], #24
+
   %b = call i8 @llvm.bitreverse.i8(i8 %a)
   ret i8 %b
 }