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llvm-project/llvm/test/CodeGen/PowerPC/constants-i64.ll

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[PowerPC] Materialize i64 constants using bit inversion Materializing full 64-bit constants on PPC64 can be expensive, requiring up to 5 instructions depending on the locations of the non-zero bits. Sometimes materializing the bit-reversed constant, and then flipping the bits, requires fewer instructions than the direct method. If so, do that instead. llvm-svn: 225132
2015-01-04 20:35:03 +08:00
; RUN: llc -mcpu=ppc64 < %s | FileCheck %s
target datalayout = "E-m:e-i64:64-n32:64"
target triple = "powerpc64-unknown-linux-gnu"
; Function Attrs: nounwind readnone
define i64 @cn1() #0 {
entry:
ret i64 281474976710655
; CHECK-LABEL: @cn1
[PowerPC] Materialize i64 constants using rotation Materializing full 64-bit constants on PPC64 can be expensive, requiring up to 5 instructions depending on the locations of the non-zero bits. Sometimes materializing a rotated constant, and then applying the inverse rotation, requires fewer instructions than the direct method. If so, do that instead. In r225132, I added support for forming constants using bit inversion. In effect, this reverts that commit and replaces it with rotation support. The bit inversion is useful for turning constants that are mostly ones into ones that are mostly zeros (thus enabling a more-efficient shift-based materialization), but the same effect can be obtained by using negative constants and a rotate, and that is at least as efficient, if not more. llvm-svn: 225135
2015-01-04 23:43:55 +08:00
; CHECK: lis [[REG1:[0-9]+]], -1
; CHECK: rldicl 3, [[REG1]], 48, 0
[PowerPC] Materialize i64 constants using bit inversion Materializing full 64-bit constants on PPC64 can be expensive, requiring up to 5 instructions depending on the locations of the non-zero bits. Sometimes materializing the bit-reversed constant, and then flipping the bits, requires fewer instructions than the direct method. If so, do that instead. llvm-svn: 225132
2015-01-04 20:35:03 +08:00
; CHECK: blr
}
[PowerPC] Materialize i64 constants using rotation Materializing full 64-bit constants on PPC64 can be expensive, requiring up to 5 instructions depending on the locations of the non-zero bits. Sometimes materializing a rotated constant, and then applying the inverse rotation, requires fewer instructions than the direct method. If so, do that instead. In r225132, I added support for forming constants using bit inversion. In effect, this reverts that commit and replaces it with rotation support. The bit inversion is useful for turning constants that are mostly ones into ones that are mostly zeros (thus enabling a more-efficient shift-based materialization), but the same effect can be obtained by using negative constants and a rotate, and that is at least as efficient, if not more. llvm-svn: 225135
2015-01-04 23:43:55 +08:00
; Function Attrs: nounwind readnone
define i64 @cnb() #0 {
entry:
ret i64 281474976710575
; CHECK-LABEL: @cnb
; CHECK: lis [[REG1:[0-9]+]], -81
; CHECK: rldicl 3, [[REG1]], 48, 0
; CHECK: blr
}
; Function Attrs: nounwind readnone
define i64 @f2n(i64 %x) #0 {
entry:
ret i64 68719476735
; CHECK-LABEL: @f2n
; CHECK: lis [[REG1:[0-9]+]], -4096
; CHECK: rldicl 3, [[REG1]], 36, 0
; CHECK: blr
}
; Function Attrs: nounwind readnone
define i64 @f3(i64 %x) #0 {
entry:
ret i64 8589934591
; CHECK-LABEL: @f3
; CHECK: lis [[REG1:[0-9]+]], -32768
; CHECK: rldicl 3, [[REG1]], 33, 0
; CHECK: blr
}
; Function Attrs: nounwind readnone
define i64 @cn2n() #0 {
entry:
ret i64 -1407374887747585
; CHECK-LABEL: @cn2n
; CHECK: lis [[REG1:[0-9]+]], -5121
; CHECK: ori [[REG2:[0-9]+]], [[REG1]], 65534
; CHECK: rldicl 3, [[REG2]], 22, 0
; CHECK: blr
}
[PowerPC] Materialize i64 constants using bit inversion Materializing full 64-bit constants on PPC64 can be expensive, requiring up to 5 instructions depending on the locations of the non-zero bits. Sometimes materializing the bit-reversed constant, and then flipping the bits, requires fewer instructions than the direct method. If so, do that instead. llvm-svn: 225132
2015-01-04 20:35:03 +08:00
attributes #0 = { nounwind readnone }