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| author | Eugene Rozenfeld <erozen@microsoft.com> | 2015-10-12 18:36:25 -0700 |
|---|---|---|
| committer | Eugene Rozenfeld <erozen@microsoft.com> | 2015-10-21 18:51:48 -0700 |
| commit | 7b4508ba9419157570a9c47e4ebc8a79dcc53a11 (patch) | |
| tree | cf3feb736ff173462fc82b71633f2d66e75ee9cc /src/jit/instrsxarch.h | |
| parent | 65b55ab02eba5fc71daadb0db9f4d4a424906dba (diff) | |
| download | coreclr-7b4508ba9419157570a9c47e4ebc8a79dcc53a11.tar.gz coreclr-7b4508ba9419157570a9c47e4ebc8a79dcc53a11.tar.bz2 coreclr-7b4508ba9419157570a9c47e4ebc8a79dcc53a11.zip | |
Generate efficient code for rotation patterns.
This change adds code to recognize rotation idioms and generate efficient instructions for them.
Two new operators are added: GT_ROL and GT_ROR.
The patterns recognized:
(x << c1) | (x >>> c2) => x rol c1
(x >>> c1) | (x << c2) => x ror c2
where c1 and c2 are constant and c1 + c2 == bitsize(x)
(x << y) | (x >>> (N - y)) => x rol y
(x >>> y) | (x << (N - y)) => x ror y
where N == bitsize(x)
(x << y & M1) | (x >>> (N - y) & M2) => x rol y
(x >>> y & M1) | (x << (N - y) & M2) => x ror y
where N == bitsize(x)
M1 & (N - 1) == N - 1
M2 & (N - 1) == N - 1
For a simple benchmark with 4 rotation patterns in a tight loop
time goes from 7.324 to 2.600 (2.8 speedup).
Rotations found and optimized in mscorlib:
System.Security.Cryptography.SHA256Managed::RotateRight
System.Security.Cryptography.SHA384Managed::RotateRight
System.Security.Cryptography.SHA512Managed::RotateRight
System.Security.Cryptography.RIPEMD160Managed:MDTransform (320 instances!)
System.Diagnostics.Tracing.EventSource.Sha1ForNonSecretPurposes::Rol1
System.Diagnostics.Tracing.EventSource.Sha1ForNonSecretPurposes::Rol5
System.Diagnostics.Tracing.EventSource.Sha1ForNonSecretPurposes::Rol30
System.Diagnostics.Tracing.EventSource.Sha1ForNonSecretPurposes::Drain
(9 instances of Sha1ForNonSecretPurposes::Rol* inlined)
Closes #1619.
Diffstat (limited to 'src/jit/instrsxarch.h')
| -rw-r--r-- | src/jit/instrsxarch.h | 7 |
1 files changed, 7 insertions, 0 deletions
diff --git a/src/jit/instrsxarch.h b/src/jit/instrsxarch.h index c0be9aae73..9f8a9956a3 100644 --- a/src/jit/instrsxarch.h +++ b/src/jit/instrsxarch.h @@ -339,6 +339,13 @@ INST2(ret , "ret" , 0, IUM_RD, 0, 0, 0x0000C3, 0x0000C2) INST2(loop , "loop" , 0, IUM_RD, 0, 0, BAD_CODE, 0x0000E2) INST2(call , "call" , 0, IUM_RD, 0, 1, 0x0010FF, 0x0000E8) +INST2(rol , "rol" , 0, IUM_RW, 0, 1, 0x0000D2, BAD_CODE) +INST2(rol_1 , "rol" , 0, IUM_RW, 0, 1, 0x0000D0, 0x0000D0) +INST2(rol_N , "rol" , 0, IUM_RW, 0, 1, 0x0000C0, 0x0000C0) +INST2(ror , "ror" , 0, IUM_RW, 0, 1, 0x0008D2, BAD_CODE) +INST2(ror_1 , "ror" , 0, IUM_RW, 0, 1, 0x0008D0, 0x0008D0) +INST2(ror_N , "ror" , 0, IUM_RW, 0, 1, 0x0008C0, 0x0008C0) + INST2(rcl , "rcl" , 0, IUM_RW, 1, 1, 0x0010D2, BAD_CODE) INST2(rcl_1 , "rcl" , 0, IUM_RW, 1, 1, 0x0010D0, 0x0010D0) INST2(rcl_N , "rcl" , 0, IUM_RW, 1, 1, 0x0010C0, 0x0010C0) |