Fix PPC unaligned 64-bit loads and stores

PPC64 supports unaligned loads and stores of 64-bit values, but
in order to use the r+i forms, the offset must be a multiple of 4.
Unfortunately, this cannot always be determined by examining the
immediate itself because it might be available only via a TOC entry.

In order to get around this issue, we additionally predicate the
selection of the r+i form on the alignment of the load or store
(forcing it to be at least 4 in order to select the r+i form).

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@177338 91177308-0d34-0410-b5e6-96231b3b80d8
This commit is contained in:
Hal Finkel 2013-03-18 23:00:58 +00:00
parent bf37bf9e21
commit 08a215c286
4 changed files with 84 additions and 6 deletions

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@ -1183,13 +1183,15 @@ bool PPCTargetLowering::getPreIndexedAddressParts(SDNode *N, SDValue &Base,
SDValue Ptr;
EVT VT;
unsigned Alignment;
if (LoadSDNode *LD = dyn_cast<LoadSDNode>(N)) {
Ptr = LD->getBasePtr();
VT = LD->getMemoryVT();
Alignment = LD->getAlignment();
} else if (StoreSDNode *ST = dyn_cast<StoreSDNode>(N)) {
Ptr = ST->getBasePtr();
VT = ST->getMemoryVT();
Alignment = ST->getAlignment();
} else
return false;
@ -1208,6 +1210,10 @@ bool PPCTargetLowering::getPreIndexedAddressParts(SDNode *N, SDValue &Base,
if (!SelectAddressRegImm(Ptr, Offset, Base, DAG))
return false;
} else {
// LDU/STU need an address with at least 4-byte alignment.
if (Alignment < 4)
return false;
// reg + imm * 4.
if (!SelectAddressRegImmShift(Ptr, Offset, Base, DAG))
return false;

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@ -555,7 +555,8 @@ def LHA8: DForm_1<42, (outs G8RC:$rD), (ins memri:$src),
PPC970_DGroup_Cracked;
def LWA : DSForm_1<58, 2, (outs G8RC:$rD), (ins memrix:$src),
"lwa $rD, $src", LdStLWA,
[(set G8RC:$rD, (sextloadi32 ixaddr:$src))]>, isPPC64,
[(set G8RC:$rD,
(aligned4sextloadi32 ixaddr:$src))]>, isPPC64,
PPC970_DGroup_Cracked;
def LHAX8: XForm_1<31, 343, (outs G8RC:$rD), (ins memrr:$src),
"lhax $rD, $src", LdStLHA,
@ -648,7 +649,7 @@ def LWZUX8 : XForm_1<31, 55, (outs G8RC:$rD, ptr_rc:$ea_result),
let canFoldAsLoad = 1, PPC970_Unit = 2 in {
def LD : DSForm_1<58, 0, (outs G8RC:$rD), (ins memrix:$src),
"ld $rD, $src", LdStLD,
[(set G8RC:$rD, (load ixaddr:$src))]>, isPPC64;
[(set G8RC:$rD, (aligned4load ixaddr:$src))]>, isPPC64;
def LDrs : DSForm_1<58, 0, (outs G8RC:$rD), (ins memrs:$src),
"ld $rD, $src", LdStLD,
[]>, isPPC64;
@ -682,6 +683,10 @@ def LDtoc_restore : DSForm_1a<58, 0, (outs), (ins),
def LDX : XForm_1<31, 21, (outs G8RC:$rD), (ins memrr:$src),
"ldx $rD, $src", LdStLD,
[(set G8RC:$rD, (load xaddr:$src))]>, isPPC64;
let isCodeGenOnly = 1 in
def LDXu : XForm_1<31, 21, (outs G8RC:$rD), (ins memrr:$src),
"ldx $rD, $src", LdStLD,
[(set G8RC:$rD, (load xaddr:$src))]>, isPPC64;
let mayLoad = 1 in
def LDU : DSForm_1<58, 1, (outs G8RC:$rD, ptr_rc:$ea_result), (ins memrix:$addr),
@ -798,7 +803,7 @@ def STWX8 : XForm_8<31, 151, (outs), (ins G8RC:$rS, memrr:$dst),
// Normal 8-byte stores.
def STD : DSForm_1<62, 0, (outs), (ins G8RC:$rS, memrix:$dst),
"std $rS, $dst", LdStSTD,
[(store G8RC:$rS, ixaddr:$dst)]>, isPPC64;
[(aligned4store G8RC:$rS, ixaddr:$dst)]>, isPPC64;
def STDX : XForm_8<31, 149, (outs), (ins G8RC:$rS, memrr:$dst),
"stdx $rS, $dst", LdStSTD,
[(store G8RC:$rS, xaddr:$dst)]>, isPPC64,
@ -833,7 +838,8 @@ def STWU8 : DForm_1a<37, (outs ptr_rc:$ea_res), (ins G8RC:$rS,
def STDU : DSForm_1a<62, 1, (outs ptr_rc:$ea_res), (ins G8RC:$rS,
s16immX4:$ptroff, ptr_rc:$ptrreg),
"stdu $rS, $ptroff($ptrreg)", LdStSTDU,
[(set ptr_rc:$ea_res, (pre_store G8RC:$rS, ptr_rc:$ptrreg,
[(set ptr_rc:$ea_res,
(aligned4pre_store G8RC:$rS, ptr_rc:$ptrreg,
iaddroff:$ptroff))]>,
RegConstraint<"$ptrreg = $ea_res">, NoEncode<"$ea_res">,
isPPC64;
@ -979,3 +985,13 @@ def : Pat<(add G8RC:$in, (PPChi tjumptable:$g, 0)),
(ADDIS8 G8RC:$in, tjumptable:$g)>;
def : Pat<(add G8RC:$in, (PPChi tblockaddress:$g, 0)),
(ADDIS8 G8RC:$in, tblockaddress:$g)>;
// Patterns to match r+r indexed loads and stores for
// addresses without at least 4-byte alignment.
def : Pat<(i64 (unaligned4sextloadi32 xoaddr:$src)),
(LWAX xoaddr:$src)>;
def : Pat<(i64 (unaligned4load xoaddr:$src)),
(LDX xoaddr:$src)>;
def : Pat<(unaligned4store G8RC:$rS, xoaddr:$dst),
(STDX G8RC:$rS, xoaddr:$dst)>;

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@ -278,6 +278,38 @@ def imm16ShiftedSExt : PatLeaf<(imm), [{
return N->getZExtValue() == (uint64_t)(int)N->getZExtValue();
}], HI16>;
// Some r+i load/store instructions (such as LD, STD, LDU, etc.) that require
// restricted memrix (offset/4) constants are alignment sensitive. If these
// offsets are hidden behind TOC entries than the values of the lower-order
// bits cannot be checked directly. As a result, we need to also incorporate
// an alignment check into the relevant patterns.
def aligned4load : PatFrag<(ops node:$ptr), (load node:$ptr), [{
return cast<LoadSDNode>(N)->getAlignment() >= 4;
}]>;
def aligned4store : PatFrag<(ops node:$val, node:$ptr),
(store node:$val, node:$ptr), [{
return cast<StoreSDNode>(N)->getAlignment() >= 4;
}]>;
def aligned4sextloadi32 : PatFrag<(ops node:$ptr), (sextloadi32 node:$ptr), [{
return cast<LoadSDNode>(N)->getAlignment() >= 4;
}]>;
def aligned4pre_store : PatFrag<
(ops node:$val, node:$base, node:$offset),
(pre_store node:$val, node:$base, node:$offset), [{
return cast<StoreSDNode>(N)->getAlignment() >= 4;
}]>;
def unaligned4load : PatFrag<(ops node:$ptr), (load node:$ptr), [{
return cast<LoadSDNode>(N)->getAlignment() < 4;
}]>;
def unaligned4store : PatFrag<(ops node:$val, node:$ptr),
(store node:$val, node:$ptr), [{
return cast<StoreSDNode>(N)->getAlignment() < 4;
}]>;
def unaligned4sextloadi32 : PatFrag<(ops node:$ptr), (sextloadi32 node:$ptr), [{
return cast<LoadSDNode>(N)->getAlignment() < 4;
}]>;
//===----------------------------------------------------------------------===//
// PowerPC Flag Definitions.

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@ -0,0 +1,24 @@
; RUN: llc < %s -mcpu=pwr7 | FileCheck %s
target datalayout = "E-p:64:64:64-i1:8:8-i8:8:8-i16:16:16-i32:32:32-i64:64:64-f32:32:32-f64:64:64-f128:128:128-v128:128:128-n32:64"
target triple = "powerpc64-unknown-linux-gnu"
define fastcc void @copy_to_conceal() #0 {
entry:
br i1 undef, label %if.then, label %if.end210
if.then: ; preds = %entry
br label %vector.body.i
vector.body.i: ; preds = %vector.body.i, %if.then
%index.i = phi i64 [ 0, %vector.body.i ], [ 0, %if.then ]
store <8 x i16> zeroinitializer, <8 x i16>* undef, align 2
br label %vector.body.i
if.end210: ; preds = %entry
ret void
; CHECK: @copy_to_conceal
; CHECK: stdx {{[0-9]+}}, 0,
}
attributes #0 = { nounwind "less-precise-fpmad"="false" "no-frame-pointer-elim"="false" "no-frame-pointer-elim-non-leaf"="true" "no-infs-fp-math"="false" "no-nans-fp-math"="false" "unsafe-fp-math"="false" "use-soft-float"="false" }