shylie/llvm-project
1
0
Fork 0
Code Issues Pull Requests Actions 6 Packages Projects Releases Wiki Activity

[Sparc] Use ANDN instead of AND if constant can be encoded more efficiently

Browse Source 
Summary:
In the case of (and reg, constant) or (or reg, constant), it can be
beneficial to use a ANDNrr/ORNrr instruction instead of ANDrr/ORrr,
if the complement of the constant can be encoded using a single SETHI
instruction instead of a SETHI/ORri pair.

If the constant has more than one use, it is probably better to keep it
in its original form.

Reviewers: jyknight, venkatra

Reviewed By: jyknight

Subscribers: fedor.sergeev, jrtc27, llvm-commits

Differential Revision: https://reviews.llvm.org/D50964

llvm-svn: 341069
This commit is contained in:
Daniel Cederman 2018-08-30 14:05:26 +00:00
parent 201f892b3b
commit 8f0bf6c19a
2 changed files with 60 additions and 0 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

18
llvm/lib/Target/Sparc/SparcInstrInfo.td
View File

@ -89,10 +89,22 @@ def HI22 : SDNodeXForm<imm, [{
MVT::i32);
}]>;
// Return the complement of a HI22 immediate value.
def HI22_not : SDNodeXForm<imm, [{
return CurDAG->getTargetConstant(~(unsigned)N->getZExtValue() >> 10, SDLoc(N),
MVT::i32);
}]>;
def SETHIimm : PatLeaf<(imm), [{
return isShiftedUInt<22, 10>(N->getZExtValue());
}], HI22>;
// The N->hasOneUse() prevents the immediate from being instantiated in both
// normal and complement form.
def SETHIimm_not : PatLeaf<(i32 imm), [{
return N->hasOneUse() && isShiftedUInt<22, 10>(~(unsigned)N->getZExtValue());
}], HI22_not>;
// Addressing modes.
def ADDRrr : ComplexPattern<iPTR, 2, "SelectADDRrr", [], []>;
def ADDRri : ComplexPattern<iPTR, 2, "SelectADDRri", [frameindex], []>;
@ -680,6 +692,12 @@ def XNORri : F3_2<2, 0b000111,
(outs IntRegs:$rd), (ins IntRegs:$rs1, simm13Op:$simm13),
"xnor $rs1, $simm13, $rd", []>;
def : Pat<(and IntRegs:$rs1, SETHIimm_not:$rs2),
(ANDNrr i32:$rs1, (SETHIi SETHIimm_not:$rs2))>;
def : Pat<(or IntRegs:$rs1, SETHIimm_not:$rs2),
(ORNrr i32:$rs1, (SETHIi SETHIimm_not:$rs2))>;
let Defs = [ICC] in {
defm ANDCC : F3_12np<"andcc", 0b010001>;
defm ANDNCC : F3_12np<"andncc", 0b010101>;

42
llvm/test/CodeGen/SPARC/sethiandn.ll Normal file
View File

@ -0,0 +1,42 @@
; NOTE: Assertions have been autogenerated by utils/update_llc_test_checks.py
; RUN: llc < %s -mtriple=sparc | FileCheck %s -check-prefix=SPARC
define i32 @test_andn(i32 %x) nounwind {
; SPARC-LABEL: test_andn:
; SPARC: ! %bb.0: ! %entry
; SPARC-NEXT: sethi 4194272, %o1
; SPARC-NEXT: retl
; SPARC-NEXT: andn %o0, %o1, %o0
entry:
%and = and i32 %x, 32767
ret i32 %and
}
define i32 @test_orn(i32 %x) nounwind {
; SPARC-LABEL: test_orn:
; SPARC: ! %bb.0: ! %entry
; SPARC-NEXT: sethi 4194272, %o1
; SPARC-NEXT: retl
; SPARC-NEXT: orn %o0, %o1, %o0
entry:
%or = or i32 %x, 32767
ret i32 %or
}
; If constant is used more than once it is probably
; better to keep it in its original form.
define i32 @test_used_more_than_once(i32 %x) nounwind {
; SPARC-LABEL: test_used_more_than_once:
; SPARC: ! %bb.0: ! %entry
; SPARC-NEXT: sethi 31, %o1
; SPARC-NEXT: or %o1, 1023, %o1
; SPARC-NEXT: or %o0, %o1, %o2
; SPARC-NEXT: and %o0, %o1, %o0
; SPARC-NEXT: retl
; SPARC-NEXT: xor %o2, %o0, %o0
entry:
%0 = or i32 %x, 32767
%and = and i32 %x, 32767
%res = xor i32 %0, %and
ret i32 %res
}