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llvm-project/llvm/test/CodeGen/AArch64/bitreverse.ll

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[SDAG] Introduce a new BITREVERSE node along with a corresponding LLVM intrinsic Several backends have instructions to reverse the order of bits in an integer. Conceptually matching such patterns is similar to @llvm.bswap, and it was mentioned in http://reviews.llvm.org/D14234 that it would be best if these patterns were matched in InstCombine instead of reimplemented in every different target. This patch introduces an intrinsic @llvm.bitreverse.i* that operates similarly to @llvm.bswap. For plumbing purposes there is also a new ISD node ISD::BITREVERSE, with simple expansion and promotion support. The intention is that InstCombine's BSWAP detection logic will be extended to support BITREVERSE too, and @llvm.bitreverse intrinsics emitted (if the backend supports lowering it efficiently). llvm-svn: 252878
2015-11-12 20:29:09 +08:00
; RUN: llc -mtriple=aarch64-eabi %s -o - | FileCheck %s
[AArch64] Add support for lowering bitreverse to the rbit instruction. Differential Revision: https://reviews.llvm.org/D28379 llvm-svn: 291575
2017-01-11 01:20:33 +08:00
; These tests just check that the plumbing is in place for @llvm.bitreverse.
[SDAG] Introduce a new BITREVERSE node along with a corresponding LLVM intrinsic Several backends have instructions to reverse the order of bits in an integer. Conceptually matching such patterns is similar to @llvm.bswap, and it was mentioned in http://reviews.llvm.org/D14234 that it would be best if these patterns were matched in InstCombine instead of reimplemented in every different target. This patch introduces an intrinsic @llvm.bitreverse.i* that operates similarly to @llvm.bswap. For plumbing purposes there is also a new ISD node ISD::BITREVERSE, with simple expansion and promotion support. The intention is that InstCombine's BSWAP detection logic will be extended to support BITREVERSE too, and @llvm.bitreverse intrinsics emitted (if the backend supports lowering it efficiently). llvm-svn: 252878
2015-11-12 20:29:09 +08:00
declare <2 x i16> @llvm.bitreverse.v2i16(<2 x i16>) readnone
define <2 x i16> @f(<2 x i16> %a) {
; CHECK-LABEL: f:
[AArch64] Add support for lowering bitreverse to the rbit instruction. Differential Revision: https://reviews.llvm.org/D28379 llvm-svn: 291575
2017-01-11 01:20:33 +08:00
; CHECK: fmov [[REG1:w[0-9]+]], s0
; CHECK-DAG: rbit [[REG2:w[0-9]+]], [[REG1]]
; CHECK-DAG: fmov s0, [[REG2]]
; CHECK-DAG: mov [[REG3:w[0-9]+]], v0.s[1]
; CHECK-DAG: rbit [[REG4:w[0-9]+]], [[REG3]]
Revert r294437 as it broke an asan buildbot. llvm-svn: 294523
2017-02-09 05:41:16 +08:00
; CHECK-DAG: ins v0.s[1], [[REG4]]
[AArch64] Add support for lowering bitreverse to the rbit instruction. Differential Revision: https://reviews.llvm.org/D28379 llvm-svn: 291575
2017-01-11 01:20:33 +08:00
; CHECK-DAG: ushr v0.2s, v0.2s, #16
[SDAG] Introduce a new BITREVERSE node along with a corresponding LLVM intrinsic Several backends have instructions to reverse the order of bits in an integer. Conceptually matching such patterns is similar to @llvm.bswap, and it was mentioned in http://reviews.llvm.org/D14234 that it would be best if these patterns were matched in InstCombine instead of reimplemented in every different target. This patch introduces an intrinsic @llvm.bitreverse.i* that operates similarly to @llvm.bswap. For plumbing purposes there is also a new ISD node ISD::BITREVERSE, with simple expansion and promotion support. The intention is that InstCombine's BSWAP detection logic will be extended to support BITREVERSE too, and @llvm.bitreverse intrinsics emitted (if the backend supports lowering it efficiently). llvm-svn: 252878
2015-11-12 20:29:09 +08:00
%b = call <2 x i16> @llvm.bitreverse.v2i16(<2 x i16> %a)
ret <2 x i16> %b
}
declare i8 @llvm.bitreverse.i8(i8) readnone
define i8 @g(i8 %a) {
; CHECK-LABEL: g:
[AArch64] Add support for lowering bitreverse to the rbit instruction. Differential Revision: https://reviews.llvm.org/D28379 llvm-svn: 291575
2017-01-11 01:20:33 +08:00
; CHECK: rbit [[REG:w[0-9]+]], w0
; CHECK-NEXT: lsr w0, [[REG]], #24
; CHECK-NEXT: ret
[SDAG] Introduce a new BITREVERSE node along with a corresponding LLVM intrinsic Several backends have instructions to reverse the order of bits in an integer. Conceptually matching such patterns is similar to @llvm.bswap, and it was mentioned in http://reviews.llvm.org/D14234 that it would be best if these patterns were matched in InstCombine instead of reimplemented in every different target. This patch introduces an intrinsic @llvm.bitreverse.i* that operates similarly to @llvm.bswap. For plumbing purposes there is also a new ISD node ISD::BITREVERSE, with simple expansion and promotion support. The intention is that InstCombine's BSWAP detection logic will be extended to support BITREVERSE too, and @llvm.bitreverse intrinsics emitted (if the backend supports lowering it efficiently). llvm-svn: 252878
2015-11-12 20:29:09 +08:00
%b = call i8 @llvm.bitreverse.i8(i8 %a)
ret i8 %b
}
[SDAG] Fix expansion of BITREVERSE Richard Trieu noted that UBSan detected an overflowing shift, and the obvious fix caused a crash. What was happening was that the shiftee (1U) was indeed too small for the possible range of shifts it had to handle, but also we were using "VT.getSizeInBits()" to get the maximum type bitwidth, but we wanted "VT.getScalarSizeInBits()" to get the vector lane size instead of the entire vector size. Use an APInt for the shift and VT.getScalarSizeInBits(). llvm-svn: 253023
2015-11-13 18:02:36 +08:00
declare <8 x i8> @llvm.bitreverse.v8i8(<8 x i8>) readnone
define <8 x i8> @g_vec(<8 x i8> %a) {
[SelectionDAG] Optimization of BITREVERSE legalization for power-of-2 integer scalar/vector types An extension of D19978, this patch replaces the default BITREVERSE evaluation of individual bit masks+shifts with block mask+shifts when we have integer elements of power-of-2 bits in size. After calling BSWAP to reverse the order of the constituent bytes (which typically follows a similar approach), every neighbouring 4-bits, 2-bits and finally 1-bit pairs are masked off and swapped over with shifts. In doing so we can significantly reduce the number of operations required. Differential Revision: https://reviews.llvm.org/D21578 llvm-svn: 276432
2016-07-23 00:46:25 +08:00
; CHECK-DAG: movi [[M1:v.*]], #15
; CHECK-DAG: movi [[M2:v.*]], #240
; CHECK: and [[A1:v.*]], v0.8b, [[M1]]
; CHECK: and [[A2:v.*]], v0.8b, [[M2]]
; CHECK-DAG: shl [[L4:v.*]], [[A1]], #4
; CHECK-DAG: ushr [[R4:v.*]], [[A2]], #4
; CHECK-DAG: orr [[V4:v.*]], [[R4]], [[L4]]
; CHECK-DAG: movi [[M3:v.*]], #51
; CHECK-DAG: movi [[M4:v.*]], #204
; CHECK: and [[A3:v.*]], [[V4]], [[M3]]
; CHECK: and [[A4:v.*]], [[V4]], [[M4]]
; CHECK-DAG: shl [[L2:v.*]], [[A3]], #2
; CHECK-DAG: ushr [[R2:v.*]], [[A4]], #2
; CHECK-DAG: orr [[V2:v.*]], [[R2]], [[L2]]
[SDAG] Fix expansion of BITREVERSE Richard Trieu noted that UBSan detected an overflowing shift, and the obvious fix caused a crash. What was happening was that the shiftee (1U) was indeed too small for the possible range of shifts it had to handle, but also we were using "VT.getSizeInBits()" to get the maximum type bitwidth, but we wanted "VT.getScalarSizeInBits()" to get the vector lane size instead of the entire vector size. Use an APInt for the shift and VT.getScalarSizeInBits(). llvm-svn: 253023
2015-11-13 18:02:36 +08:00
[SelectionDAG] Optimization of BITREVERSE legalization for power-of-2 integer scalar/vector types An extension of D19978, this patch replaces the default BITREVERSE evaluation of individual bit masks+shifts with block mask+shifts when we have integer elements of power-of-2 bits in size. After calling BSWAP to reverse the order of the constituent bytes (which typically follows a similar approach), every neighbouring 4-bits, 2-bits and finally 1-bit pairs are masked off and swapped over with shifts. In doing so we can significantly reduce the number of operations required. Differential Revision: https://reviews.llvm.org/D21578 llvm-svn: 276432
2016-07-23 00:46:25 +08:00
; CHECK-DAG: movi [[M5:v.*]], #85
; CHECK-DAG: movi [[M6:v.*]], #170
; CHECK: and [[A5:v.*]], [[V2]], [[M5]]
; CHECK: and [[A6:v.*]], [[V2]], [[M6]]
; CHECK-DAG: shl [[L1:v.*]], [[A5]], #1
; CHECK-DAG: ushr [[R1:v.*]], [[A6]], #1
; CHECK: orr [[V1:v.*]], [[R1]], [[L1]]
[SDAG] Fix expansion of BITREVERSE Richard Trieu noted that UBSan detected an overflowing shift, and the obvious fix caused a crash. What was happening was that the shiftee (1U) was indeed too small for the possible range of shifts it had to handle, but also we were using "VT.getSizeInBits()" to get the maximum type bitwidth, but we wanted "VT.getScalarSizeInBits()" to get the vector lane size instead of the entire vector size. Use an APInt for the shift and VT.getScalarSizeInBits(). llvm-svn: 253023
2015-11-13 18:02:36 +08:00
[SelectionDAG] Optimization of BITREVERSE legalization for power-of-2 integer scalar/vector types An extension of D19978, this patch replaces the default BITREVERSE evaluation of individual bit masks+shifts with block mask+shifts when we have integer elements of power-of-2 bits in size. After calling BSWAP to reverse the order of the constituent bytes (which typically follows a similar approach), every neighbouring 4-bits, 2-bits and finally 1-bit pairs are masked off and swapped over with shifts. In doing so we can significantly reduce the number of operations required. Differential Revision: https://reviews.llvm.org/D21578 llvm-svn: 276432
2016-07-23 00:46:25 +08:00
; CHECK: ret
[SDAG] Fix expansion of BITREVERSE Richard Trieu noted that UBSan detected an overflowing shift, and the obvious fix caused a crash. What was happening was that the shiftee (1U) was indeed too small for the possible range of shifts it had to handle, but also we were using "VT.getSizeInBits()" to get the maximum type bitwidth, but we wanted "VT.getScalarSizeInBits()" to get the vector lane size instead of the entire vector size. Use an APInt for the shift and VT.getScalarSizeInBits(). llvm-svn: 253023
2015-11-13 18:02:36 +08:00
%b = call <8 x i8> @llvm.bitreverse.v8i8(<8 x i8> %a)
ret <8 x i8> %b
}