This change handles a another case for generating the bic instruction

when a compile time constant is known.  This occurs when implicitly zero 
extending function arguments from 16 bits to 32 bits.  The 8 bit case doesn't
need to be handled, as the 8 bit constants are encoded directly, thereby
not needing a separate load instruction to form the constant into a register.

<rdar://problem/11481151>


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@158659 91177308-0d34-0410-b5e6-96231b3b80d8
This commit is contained in:
Joel Jones 2012-06-18 14:51:32 +00:00
parent 457dfbac8a
commit 96ef284da4
2 changed files with 50 additions and 0 deletions

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@ -62,6 +62,15 @@ def t2_so_imm_neg_XFORM : SDNodeXForm<imm, [{
return CurDAG->getTargetConstant(-((int)N->getZExtValue()), MVT::i32);
}]>;
// so_imm_notSext_XFORM - Return a so_imm value packed into the format
// described for so_imm_notSext def below, with sign extension from 16
// bits.
def t2_so_imm_notSext16_XFORM : SDNodeXForm<imm, [{
APInt apIntN = N->getAPIntValue();
unsigned N16bitSignExt = apIntN.trunc(16).sext(32).getZExtValue();
return CurDAG->getTargetConstant(~N16bitSignExt, MVT::i32);
}]>;
// t2_so_imm - Match a 32-bit immediate operand, which is an
// 8-bit immediate rotated by an arbitrary number of bits, or an 8-bit
// immediate splatted into multiple bytes of the word.
@ -86,6 +95,17 @@ def t2_so_imm_not : Operand<i32>, PatLeaf<(imm), [{
let ParserMatchClass = t2_so_imm_not_asmoperand;
}
// t2_so_imm_notSext - match an immediate that is a complement of a t2_so_imm
// if the upper 16 bits are zero.
def t2_so_imm_notSext : Operand<i32>, PatLeaf<(imm), [{
APInt apIntN = N->getAPIntValue();
if (!apIntN.isIntN(16)) return false;
unsigned N16bitSignExt = apIntN.trunc(16).sext(32).getZExtValue();
return ARM_AM::getT2SOImmVal(~N16bitSignExt) != -1;
}], t2_so_imm_notSext16_XFORM> {
let ParserMatchClass = t2_so_imm_not_asmoperand;
}
// t2_so_imm_neg - Match an immediate that is a negation of a t2_so_imm.
def t2_so_imm_neg_asmoperand : AsmOperandClass { let Name = "T2SOImmNeg"; }
def t2_so_imm_neg : Operand<i32>, PatLeaf<(imm), [{
@ -2332,6 +2352,17 @@ let AddedComplexity = 1 in
def : T2Pat<(and rGPR:$src, t2_so_imm_not:$imm),
(t2BICri rGPR:$src, t2_so_imm_not:$imm)>;
// top16Zero - answer true if the upper 16 bits of $src are 0, false otherwise
def top16Zero: PatLeaf<(i32 rGPR:$src), [{
return CurDAG->MaskedValueIsZero(SDValue(N,0), APInt::getHighBitsSet(32, 16));
}]>;
// so_imm_notSext is needed instead of so_imm_not, as the value of imm
// will match the extended, not the original bitWidth for $src.
def : T2Pat<(and top16Zero:$src, t2_so_imm_notSext:$imm),
(t2BICri rGPR:$src, t2_so_imm_notSext:$imm)>;
// FIXME: Disable this pattern on Darwin to workaround an assembler bug.
def : T2Pat<(or rGPR:$src, t2_so_imm_not:$imm),
(t2ORNri rGPR:$src, t2_so_imm_not:$imm)>,

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@ -0,0 +1,19 @@
; RUN: llc %s -o - | FileCheck %s
; ModuleID = 'bic.c'
target triple = "thumbv7-apple-ios3.0.0"
define zeroext i16 @foo16(i16 zeroext %f) nounwind readnone optsize ssp {
entry:
; CHECK: .thumb_func _foo16
; CHECK: {{bic[^#]*#3}}
%and = and i16 %f, -4
ret i16 %and
}
define i32 @foo32(i32 %f) nounwind readnone optsize ssp {
entry:
; CHECK: .thumb_func _foo32
; CHECK: {{bic[^#]*#3}}
%and = and i32 %f, -4
ret i32 %and
}