kernel/eka/common/arm/cheap.cia
changeset 149 d9f1e5bfe28c
parent 135 5e441a173c63
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135:5e441a173c63 149:d9f1e5bfe28c
     1 // Copyright (c) 1994-2009 Nokia Corporation and/or its subsidiary(-ies).
       
     2 // All rights reserved.
       
     3 // This component and the accompanying materials are made available
       
     4 // under the terms of the License "Eclipse Public License v1.0"
       
     5 // which accompanies this distribution, and is available
       
     6 // at the URL "http://www.eclipse.org/legal/epl-v10.html".
       
     7 //
       
     8 // Initial Contributors:
       
     9 // Nokia Corporation - initial contribution.
       
    10 //
       
    11 // Contributors:
       
    12 //
       
    13 // Description:
       
    14 // e32\common\arm\cheap.cia
       
    15 // 
       
    16 //
       
    17 
       
    18 #include <e32cia.h>
       
    19 #include "../common.h"
       
    20 
       
    21 #if defined(__HEAP_MACHINE_CODED__) && !defined(_DEBUG)
       
    22 GLREF_C void RHeap_PanicBadAllocatedCellSize();
       
    23 GLREF_C void RHeap_PanicBadNextCell();
       
    24 GLREF_C void RHeap_PanicBadPrevCell();
       
    25 GLREF_C void RHeap_PanicBadCellAddress();
       
    26 
       
    27 IMPORT_D extern const TInt KHeapShrinkHysRatio;
       
    28 
       
    29 
       
    30 __NAKED__ RHeap::SCell* RHeap::DoAlloc(TInt /*aSize*/, SCell*& /*aLastFree*/)
       
    31 //
       
    32 // Allocate a cell.
       
    33 //
       
    34 	{
       
    35 	asm("stmfd sp!, {r4,r5,lr} ");
       
    36 	asm("mov r4, r0 ");										// r4=this
       
    37 	asm("add r3, r0, #%a0" : : "i" _FOFF(RHeap,iFree));		// r3=pP=&iFree
       
    38 	asm("ldr r0, [r3, #4] ");								// r0=pC=pP->next
       
    39 	asm("cmp r0, #0 ");
       
    40 	asm("beq 0f ");								// if no free cells, alloc failed
       
    41 
       
    42 	// optimised unfolded scanning loop
       
    43 	asm("2: ");
       
    44 	asm("ldmia r0, {r12,r14} ");				// r12=pC->size, r14=pC->next
       
    45 	asm("cmp r1, r12 ");						// compare aSize to size
       
    46 	asm("movhi r3, r0 ");						// if aSize>size, pP=pC
       
    47 	asm("movhis r0, r14 ");						// and pC=pC->next
       
    48 #ifndef __CPU_ARMV6 // don't unroll on armv6
       
    49 	asm("ldmhiia r0, {r12,r14} ");				// r12=pC->size, r14=pC->next
       
    50 	asm("cmphi r1, r12 ");						// compare aSize to size
       
    51 	asm("movhi r3, r0 ");						// if aSize>size, pP=pC
       
    52 	asm("movhis r0, r14 ");						// and pC=pC->next
       
    53 #endif
       
    54 	asm("bhi 2b ");								// branch back if scan not finished
       
    55 	
       
    56 	asm("1: ");
       
    57 	asm("subs r5, r12, r1 ");					// r5 = pC->len - aSize
       
    58 	asm("ldrhs r2, [r4, #%a0]" : : "i" _FOFF(RHeap,iMinCell));		// if big enough, r2=iMinCell
       
    59 	asm("blo 0f ");								// branch if no free cell was big enough
       
    60 	asm("cmp r5, r2 ");							// leftover big enough?
       
    61 	asm("movlo r1, r12 ");						// if not, aSize=pC->len ...
       
    62 	asm("strlo r14, [r3, #4] ");				// ... and pP->next = pC->next
       
    63 	asm("addhs r2, r0, r1 ");					// else r2 = pE = address of new free cell ...
       
    64 	asm("stmhsia r2, {r5, r14} ");				// ... pE->len = pC->len - aSize, pE->next = pC->next ...
       
    65 	asm("strhs r2, [r3, #4] ");					// ... and pP->next = pE
       
    66 	asm("str r1, [r0] ");						// pC->len = aSize
       
    67 	__POPRET("r4,r5,");							// restore and exit, return pC
       
    68 
       
    69 	asm("0: ");
       
    70 	asm("str r3, [r2] ");						// alloc failed - aLastFree=pP
       
    71 	asm("mov r0, #0 ");							// return NULL
       
    72 	__POPRET("r4,r5,");
       
    73 	}
       
    74 
       
    75 __NAKED__ void RHeap::DoFree(SCell* /*pC*/)
       
    76 //
       
    77 // Free a cell.
       
    78 //
       
    79 	{
       
    80 	asm("add r2, r0, #%a0" : : "i" _FOFF(RHeap,iFree));	// r2=pP=&iFree
       
    81 	asm("ldr r3, [r2, #4] ");					// r3=pE=pP->next
       
    82 	asm("stmfd sp!, {r4, r5} ");
       
    83 
       
    84 	asm("1: ");
       
    85 	asm("cmp r3, #0 ");						// check if pE=NULL
       
    86 	asm("cmphi r1, r3 ");					// if not, check if pC>pE
       
    87 	asm("movhi r2, r3 ");					// if so, pP=pE
       
    88 	asm("ldrhi r3, [r3, #4] ");				// and pE=pE->next
       
    89 #ifndef __CPU_ARMV6    // don't unroll on armv6
       
    90 	asm("cmphi r3, #0 ");					// check if pE=NULL
       
    91 	asm("cmphi r1, r3 ");					// if not, check if pC>pE
       
    92 	asm("movhi r2, r3 ");					// if so, pP=pE
       
    93 	asm("ldrhi r3, [r3, #4] ");				// and pE=pE->next
       
    94 #endif
       
    95 	asm("bhi 1b ");							// loop if free cell position not found
       
    96 
       
    97 	asm("ldr r4, [r1, #0] ");				// r4=pC->len
       
    98 	asm("cmp r3, #0 ");						// is there a following free cell ?
       
    99 	asm("streq r3, [r1, #4] ");				// if not, pC->next=NULL
       
   100 	asm("beq 2f ");							// and skip next section
       
   101 	asm("add r5, r1, r4 ");					// r5=pN=pC + pC->len (cell after pC)
       
   102 	asm("cmp r5, r3 ");						// compare pN with pE
       
   103 	asm("ldmeqia r3, {r5, r12} ");			// if pN==pE, r5=pE->len, r12=pE->next
       
   104 	asm("blhi " CSM_Z22RHeap_PanicBadNextCellv );	// if pN>pE, panic
       
   105 	asm("strne r3, [r1, #4] ");				// if pN<pE, pC->next=pE
       
   106 	asm("addeq r4, r4, r5 ");				// if pN==pE r4 = pC->len + pE->len
       
   107 	asm("stmeqia r1, {r4,r12} ");			// if pN==pE pC->len+=pE->len, pC->next=pE->next
       
   108 	asm("2: ");
       
   109 	asm("ldr r3, [r2, #0] ");				// r3=pP->len
       
   110 	asm("sub r5, r1, r2 ");					// r5=pC-pP (gap between preceding free cell and this one)
       
   111 	asm("cmp r5, r3 ");						// compare gap with predecessor length
       
   112 	asm("ldreq r12, [r1, #4] ");			// if predecessor is adjacent, r12=pC->next
       
   113 	asm("bllo RHeap_PanicBadPrevCell__Fv ");	// if predecessor overlaps, panic
       
   114 	asm("addeq r4, r4, r3 ");				// if predecessor is adjacent, r4=pC->len + pP->len
       
   115 	asm("stmeqia r2, {r4,r12} ");			// if predecessor is adjacent, pP->len+=pC->len, pP->next=pC->next
       
   116 	asm("strne r1, [r2, #4] ");				// else pP->next = pC
       
   117 	asm("moveq r1, r2 ");					// if predecessor is adjacent, pC=pP (final amalgamated free cell)
       
   118 	asm("3: ");
       
   119 	asm("ldr r12, [r0, #%a0]" : : "i" _FOFF(RHeap,iTop));	// r12=iTop
       
   120 	asm("add r3, r1, r4 ");					// end of amalgamated free cell
       
   121 	asm("cmp r3, r12 ");					// end of amalgamated free cell = iTop ?
       
   122 	asm("ldmneia sp!, {r4,r5} ");			// restore registers
       
   123 	__JUMP(ne,lr);							// if not, finished
       
   124 	asm("ldr r12, [r0, #%a0]" : : "i" _FOFF(RHeap,iFlags));	// r12=iFlags
       
   125 	asm("tst r12, #%a0" : : "i" ((TInt)RAllocator::EFixedSize));	// check fixed size flag
       
   126 	asm("ldmneia sp!, {r4,r5} ");			// restore registers
       
   127 	__JUMP(ne,lr);							// if set, finished
       
   128 	asm("ldr r2, [r0, #%a0]" : : "i" _FOFF(RHeap,iGrowBy));	// r2=iGrowBy
       
   129 	asm("mov r3, r2, LSR #8");				// r3=iGrowBy>>8
       
   130 	asm("ldr r2, const_addr");				// r2=&KHeapShrinkHysRatio
       
   131 	asm("ldr r5, [r2]");					// r5=KHeapShrinkHysRatio
       
   132 	asm("mul r2, r5, r3");					// r2=KHeapShrinkHysRatio*(iGrowBy>>8) - low order bits
       
   133 	asm("cmp r4, r2");						// compare len(r4) to (iGrowBy>>8)*KHeapShrinkHysRatio(r2)
       
   134 	asm("ldmia sp!, {r4,r5} ");				// restore registers
       
   135 	__JUMP(lo,lr);							// if less, finished
       
   136 	asm("b Reduce__5RHeapPQ25RHeap5SCell ");	// else reduce heap
       
   137 	
       
   138 	asm("const_addr:");
       
   139 	asm(".word %a0" : : "i" ((TInt)&KHeapShrinkHysRatio));	
       
   140 	}
       
   141 #endif
       
   142