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| author | Andrea Di Biagio <Andrea_DiBiagio@sn.scee.net> | 2014-05-19 20:38:59 +0000 |
|---|---|---|
| committer | Andrea Di Biagio <Andrea_DiBiagio@sn.scee.net> | 2014-05-19 20:38:59 +0000 |
| commit | 8e4a223f7bb3ee0ae6a0888b8e670a6bd4983a0a (patch) | |
| tree | 629d5a730a36b7a4fafafba32d37a8c012b8ff8b /lib/Target/X86/X86InstrInfo.td | |
| parent | 86ad7b70cb994a9ebde84053026e560a37061ce9 (diff) | |
| download | llvm-8e4a223f7bb3ee0ae6a0888b8e670a6bd4983a0a.tar.gz llvm-8e4a223f7bb3ee0ae6a0888b8e670a6bd4983a0a.tar.bz2 llvm-8e4a223f7bb3ee0ae6a0888b8e670a6bd4983a0a.tar.xz | |
[X86] Add ISel patterns to improve the selection of TZCNT and LZCNT.
Instructions TZCNT (requires BMI1) and LZCNT (requires LZCNT), always
provide the operand size as output if the input operand is zero.
We can take advantage of this knowledge during instruction selection
stage in order to simplify a few corner case.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@209159 91177308-0d34-0410-b5e6-96231b3b80d8
Diffstat (limited to 'lib/Target/X86/X86InstrInfo.td')
| -rw-r--r-- | lib/Target/X86/X86InstrInfo.td | 81 |
1 files changed, 81 insertions, 0 deletions
diff --git a/lib/Target/X86/X86InstrInfo.td b/lib/Target/X86/X86InstrInfo.td index 23cd496ade..0d97669b22 100644 --- a/lib/Target/X86/X86InstrInfo.td +++ b/lib/Target/X86/X86InstrInfo.td @@ -2002,6 +2002,46 @@ let Predicates = [HasLZCNT], Defs = [EFLAGS] in { (implicit EFLAGS)]>, XS; } +let Predicates = [HasLZCNT] in { + def : Pat<(X86cmov (ctlz GR16:$src), (i16 16), (X86_COND_E), + (X86cmp GR16:$src, (i16 0))), + (LZCNT16rr GR16:$src)>; + def : Pat<(X86cmov (ctlz GR32:$src), (i32 32), (X86_COND_E), + (X86cmp GR32:$src, (i32 0))), + (LZCNT32rr GR32:$src)>; + def : Pat<(X86cmov (ctlz GR64:$src), (i64 64), (X86_COND_E), + (X86cmp GR64:$src, (i64 0))), + (LZCNT64rr GR64:$src)>; + def : Pat<(X86cmov (i16 16), (ctlz GR16:$src), (X86_COND_E), + (X86cmp GR16:$src, (i16 0))), + (LZCNT16rr GR16:$src)>; + def : Pat<(X86cmov (i32 32), (ctlz GR32:$src), (X86_COND_E), + (X86cmp GR32:$src, (i32 0))), + (LZCNT32rr GR32:$src)>; + def : Pat<(X86cmov (i64 64), (ctlz GR64:$src), (X86_COND_E), + (X86cmp GR64:$src, (i64 0))), + (LZCNT64rr GR64:$src)>; + + def : Pat<(X86cmov (ctlz (loadi16 addr:$src)), (i16 16), (X86_COND_E), + (X86cmp (loadi16 addr:$src), (i16 0))), + (LZCNT16rm addr:$src)>; + def : Pat<(X86cmov (ctlz (loadi32 addr:$src)), (i32 32), (X86_COND_E), + (X86cmp (loadi32 addr:$src), (i32 0))), + (LZCNT32rm addr:$src)>; + def : Pat<(X86cmov (ctlz (loadi64 addr:$src)), (i64 64), (X86_COND_E), + (X86cmp (loadi64 addr:$src), (i64 0))), + (LZCNT64rm addr:$src)>; + def : Pat<(X86cmov (i16 16), (ctlz (loadi16 addr:$src)), (X86_COND_E), + (X86cmp (loadi16 addr:$src), (i16 0))), + (LZCNT16rm addr:$src)>; + def : Pat<(X86cmov (i32 32), (ctlz (loadi32 addr:$src)), (X86_COND_E), + (X86cmp (loadi32 addr:$src), (i32 0))), + (LZCNT32rm addr:$src)>; + def : Pat<(X86cmov (i64 64), (ctlz (loadi64 addr:$src)), (X86_COND_E), + (X86cmp (loadi64 addr:$src), (i64 0))), + (LZCNT64rm addr:$src)>; +} + //===----------------------------------------------------------------------===// // BMI Instructions // @@ -2078,6 +2118,47 @@ let Predicates = [HasBMI] in { (BLSI64rr GR64:$src)>; } +let Predicates = [HasBMI] in { + def : Pat<(X86cmov (cttz GR16:$src), (i16 16), (X86_COND_E), + (X86cmp GR16:$src, (i16 0))), + (TZCNT16rr GR16:$src)>; + def : Pat<(X86cmov (cttz GR32:$src), (i32 32), (X86_COND_E), + (X86cmp GR32:$src, (i32 0))), + (TZCNT32rr GR32:$src)>; + def : Pat<(X86cmov (cttz GR64:$src), (i64 64), (X86_COND_E), + (X86cmp GR64:$src, (i64 0))), + (TZCNT64rr GR64:$src)>; + def : Pat<(X86cmov (i16 16), (cttz GR16:$src), (X86_COND_E), + (X86cmp GR16:$src, (i16 0))), + (TZCNT16rr GR16:$src)>; + def : Pat<(X86cmov (i32 32), (cttz GR32:$src), (X86_COND_E), + (X86cmp GR32:$src, (i32 0))), + (TZCNT32rr GR32:$src)>; + def : Pat<(X86cmov (i64 64), (cttz GR64:$src), (X86_COND_E), + (X86cmp GR64:$src, (i64 0))), + (TZCNT64rr GR64:$src)>; + + def : Pat<(X86cmov (cttz (loadi16 addr:$src)), (i16 16), (X86_COND_E), + (X86cmp (loadi16 addr:$src), (i16 0))), + (TZCNT16rm addr:$src)>; + def : Pat<(X86cmov (cttz (loadi32 addr:$src)), (i32 32), (X86_COND_E), + (X86cmp (loadi32 addr:$src), (i32 0))), + (TZCNT32rm addr:$src)>; + def : Pat<(X86cmov (cttz (loadi64 addr:$src)), (i64 64), (X86_COND_E), + (X86cmp (loadi64 addr:$src), (i64 0))), + (TZCNT64rm addr:$src)>; + def : Pat<(X86cmov (i16 16), (cttz (loadi16 addr:$src)), (X86_COND_E), + (X86cmp (loadi16 addr:$src), (i16 0))), + (TZCNT16rm addr:$src)>; + def : Pat<(X86cmov (i32 32), (cttz (loadi32 addr:$src)), (X86_COND_E), + (X86cmp (loadi32 addr:$src), (i32 0))), + (TZCNT32rm addr:$src)>; + def : Pat<(X86cmov (i64 64), (cttz (loadi64 addr:$src)), (X86_COND_E), + (X86cmp (loadi64 addr:$src), (i64 0))), + (TZCNT64rm addr:$src)>; +} + + multiclass bmi_bextr_bzhi<bits<8> opc, string mnemonic, RegisterClass RC, X86MemOperand x86memop, Intrinsic Int, PatFrag ld_frag> { |