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// picoChip ASM file

//

//   Support for 32-bit unsigned division/modulus.

//

//   Copyright (C) 2003, 2004, 2005, 2008, 2009  Free Software Foundation, Inc.

//   Contributed by picoChip Designs Ltd.

//   Maintained by Daniel Towner (daniel.towner@picochip.com)

//

//   This file is free software; you can redistribute it and/or modify it

//   under the terms of the GNU General Public License as published by the

//   Free Software Foundation; either version 3, or (at your option) any

//   later version.

//

//   This file is distributed in the hope that it will be useful, but

//   WITHOUT ANY WARRANTY; without even the implied warranty of

//   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU

//   General Public License for more details.

//

//   Under Section 7 of GPL version 3, you are granted additional

//   permissions described in the GCC Runtime Library Exception, version

//   3.1, as published by the Free Software Foundation.

//

//   You should have received a copy of the GNU General Public License and

//   a copy of the GCC Runtime Library Exception along with this program;

//   see the files COPYING3 and COPYING.RUNTIME respectively.  If not, see

//   .

.section .text

.align 8

.global __udivmodsi4

__udivmodsi4:

_picoMark_FUNCTION_BEGIN=

// picoChip Function Prologue : &__udivmodsi4 = 24 bytes

        // Schedule the register saves alongside the special cases, so that

        // if the special cases fail, the registers will have already

        // been stored onto the stack.

        SUB.0 R3,R1,r15 \ STL R[13:12],(FP)-1

        BHS skipCommonCase \ STL R[9:8],(FP)-4

=->     SUB.0 R2,1,r15 \ STL R[11:10],(FP)-3

_L2:

        // Flags set above, and in _L2 caller.

        BNE restOfCode

=->     SUB.0 R3,0,r15

        BNE restOfCode

=->     COPY.0 R0,R4 \ COPY.1 R1,R5

        JR (R12)        // Return to caller

=->     COPY.0 0,R6 \ COPY.1 0,R7

        // Never reach here

skipCommonCase:

        SUB.0 R3,R1,r15

        BNE _L3 // (Reversed branch)

=->     SUB.0 R2,R0,r15 // Must be set in delay slot, so ready by _L9

_L9:

        BLO _L2 // (Reversed branch)

=->     SUB.0 R2,1,r15

_L3:

        SUB.0 R2,R0,r15

        BEQ _L10        // (Reversed branch)

=->     SUB.0 R1,R3,r15 // Set flags for branch at _L10

_L4:

        // greater than

        COPY.0 0,R4 \ COPY.1 0,R5 \ JR (R12)    // Return to caller

=->     COPY.0 R0,R6 \ COPY.1 R1,R7

        // Doesn't reach here.

_L10:

        // Flags set in _L10 call delay slot.

        BNE _L4

=->     COPY.0 1,R4 \ COPY.1 0,R5

        JR (R12)        // Return to caller

=->     COPY.0 0,R6 \ COPY.1 0,R7

restOfCode:

// Prologue

        // Register saves scheduled alongside special cases above.

        ADD.0 FP,-20,FP \ STW R14,(FP)-4

        // The following can be scheduled together.

        // dividend in R[9:8] (from R[1:0])

        // divisor in R[7:6] (from R[3:2])

        // R14 := clzsi2 (dividend)

        // R0 := clzsi2 (divisor)

        JL (&__clzsi2) \ COPY.0 R0,R8 \ COPY.1 R1,R9

=->     COPY.0 R2,R6 \ COPY.1 R3,R7

        COPY.0 R0,R14 \ JL (&__clzsi2)

=->     COPY.0 R6,R0 \ COPY.1 R7,R1

        // R14 := R0 - R14

        SUB.0 R0,R14,R14

        ADD.0 R14,1,R0  // R0 := R14 + 1 (HI)

        // R[11:10] = R[7,6] << R14

        SUB.0 15,R14,r15

        LSL.0 R6,R14,R11 \ BLT setupDivstepLoop

=->     SUB.0 0,R14,R4 \ COPY.1 0,R10

        // Zero shift is a special case. Shifting by zero within a 16-bit

        // source object is fine, but don't execute the OR of the right-shift

        // into the final result.

        LSL.0 R7,R14,R11 \ BEQ setupDivstepLoop

=->     LSL.0 R6,R14,R10

        LSR.0 R6,R4,R4

        OR.0 R11,R4,R11

setupDivstepLoop:

        // R[5:4] := R[9:8] (SI)

        COPY.0 R8,R4 \ COPY.1 R9,R5

        COPY.0 0,R6 \ COPY.1 R0,R8

        // Store original value of loopCount for use after the loop.

        // The Subtraction is handled in the tail of the loop iteration

        // after this point.

        SUB.0 R4,R10,R0 \ COPY.1 R8,R14

        // workingResult in R4,5,6

        // temps in r0,1,2 and r7

        // alignedDivisor in R10,11

        // loopCount in r8

        // r3, r9 scratch, used for renaming.

loopStart:

        // R0 := R4 - zeroExtend (R10) - only need 33-bits (i.e., 48-bits)

        SUBB.0 R5,R11,R1 \ LSR.1 R0,15,R3

        SUBB.0 R6,0,R2 \ LSR.1 R1,15,R6

        // if (carry) goto shiftOnly

        SUB.0 R8,1,R8 \ BNE shiftOnly

=->     LSR.0 R4,15,R7 \ LSL.1 R1,1,R9

        OR.0 [LSL R0,1],1,R4 \ BNE loopStart

=->     SUB.0 R4,R10,R0 \ OR.1 R9,R3,R5

        BRA loopEnd

shiftOnly:

        OR.0 [LSL R5,1],R7,R5 \ BNE loopStart \ LSR.1 R5,15,R6

=->     SUB.0 [LSL R4,1],R10,R0 \LSL.1 R4,1,R4

// End of loop

loopEnd:

        // Schedule the computation of the upper word after shifting

        // alongside the decision over whether to branch, and the register

        // restores.

        // R10 is filled with a useful constant.

        SUB.0 15,r14,r15 \ LDL (FP)4,R[13:12]

        SUB.1 0,R14,R1 // Don't set flags!

        LSL.0 R6,R1,R3 \ LDL (FP)-4,R[9:8]

        BLT remainderHasMoreThan16Bits \ LSR.0 R5,R14,R7 \ COPY.1 -1,R10

=->     LSL.0 R5,R1,R2 \ OR.1 R7,R3,R3

        LSR.0 R4,R14,R3 \ COPY.1 R3,R7

        BRA epilogue \ LSR.0 -1,R1,R0 \ COPY.1 0,R5

=->     OR.0 R3,R2,R6 \ AND.1 R0,R4,R4

remainderHasMoreThan16Bits:

        LSL.0 R10,R14,R1 \ COPY.1 R3,R6

        XOR.0 R10,R1,R1 \ COPY.1 0,R7

        AND.0 R1,R5,R5

epilogue:

        JR (R12) \ LDW (FP)-4,R14

=->     LDL (FP)-3,R[11:10]

_picoMark_FUNCTION_END=

// picoChip Function Epilogue : udivmodsi4

//============================================================================

// All DWARF information between this marker, and the END OF DWARF

// marker should be included in the source file. Search for

// FUNCTION_STACK_SIZE_GOES_HERE and FUNCTION NAME GOES HERE, and

// provide the relevent information. Add markers called

// _picoMark_FUNCTION_BEGIN and _picoMark_FUNCTION_END around the

// function in question.

//============================================================================

//============================================================================

// Frame information.

//============================================================================

.section .debug_frame

_picoMark_DebugFrame=

// Common CIE header.

.unalignedInitLong _picoMark_CieEnd-_picoMark_CieBegin

_picoMark_CieBegin=

.unalignedInitLong 0xffffffff

.initByte 0x1   // CIE Version

.ascii 16#0#    // CIE Augmentation

.uleb128 0x1    // CIE Code Alignment Factor

.sleb128 2      // CIE Data Alignment Factor

.initByte 0xc   // CIE RA Column

.initByte 0xc   // DW_CFA_def_cfa

.uleb128 0xd

.uleb128 0x0

.align 2

_picoMark_CieEnd=

// FDE

_picoMark_LSFDE0I900821033007563=

.unalignedInitLong _picoMark_FdeEnd-_picoMark_FdeBegin

_picoMark_FdeBegin=

.unalignedInitLong _picoMark_DebugFrame // FDE CIE offset

.unalignedInitWord _picoMark_FUNCTION_BEGIN     // FDE initial location

.unalignedInitWord _picoMark_FUNCTION_END-_picoMark_FUNCTION_BEGIN

.initByte 0xe   // DW_CFA_def_cfa_offset

.uleb128 0x18   // <-- FUNCTION_STACK_SIZE_GOES_HERE

.initByte 0x4   // DW_CFA_advance_loc4

.unalignedInitLong _picoMark_FUNCTION_END-_picoMark_FUNCTION_BEGIN

.initByte 0xe   // DW_CFA_def_cfa_offset

.uleb128 0x0

.align 2

_picoMark_FdeEnd=

//============================================================================

// Abbrevation information.

//============================================================================

.section .debug_abbrev

_picoMark_ABBREVIATIONS=

.section .debug_abbrev

        .uleb128 0x1    // (abbrev code)

        .uleb128 0x11   // (TAG: DW_TAG_compile_unit)

        .initByte 0x1   // DW_children_yes

        .uleb128 0x10   // (DW_AT_stmt_list)

        .uleb128 0x6    // (DW_FORM_data4)

        .uleb128 0x12   // (DW_AT_high_pc)

        .uleb128 0x1    // (DW_FORM_addr)

        .uleb128 0x11   // (DW_AT_low_pc)

        .uleb128 0x1    // (DW_FORM_addr)

        .uleb128 0x25   // (DW_AT_producer)

        .uleb128 0x8    // (DW_FORM_string)

        .uleb128 0x13   // (DW_AT_language)

        .uleb128 0x5    // (DW_FORM_data2)

        .uleb128 0x3    // (DW_AT_name)

        .uleb128 0x8    // (DW_FORM_string)

.initByte 0x0

.initByte 0x0

        .uleb128 0x2    ;# (abbrev code)

        .uleb128 0x2e   ;# (TAG: DW_TAG_subprogram)

.initByte 0x0   ;# DW_children_no

        .uleb128 0x3    ;# (DW_AT_name)

        .uleb128 0x8    ;# (DW_FORM_string)

        .uleb128 0x11   ;# (DW_AT_low_pc)

        .uleb128 0x1    ;# (DW_FORM_addr)

        .uleb128 0x12   ;# (DW_AT_high_pc)

        .uleb128 0x1    ;# (DW_FORM_addr)

.initByte 0x0

.initByte 0x0

.initByte 0x0

//============================================================================

// Line information. DwarfLib requires this to be present, but it can

// be empty.

//============================================================================

.section .debug_line

_picoMark_LINES=

//============================================================================

// Debug Information

//============================================================================

.section .debug_info

//Fixed header.

.unalignedInitLong _picoMark_DEBUG_INFO_END-_picoMark_DEBUG_INFO_BEGIN

_picoMark_DEBUG_INFO_BEGIN=

.unalignedInitWord 0x2

.unalignedInitLong _picoMark_ABBREVIATIONS

.initByte 0x2

// Compile unit information.

.uleb128 0x1    // (DIE 0xb) DW_TAG_compile_unit)

.unalignedInitLong _picoMark_LINES

.unalignedInitWord _picoMark_FUNCTION_END

.unalignedInitWord _picoMark_FUNCTION_BEGIN

// Producer is `picoChip'

.ascii 16#70# 16#69# 16#63# 16#6f# 16#43# 16#68# 16#69# 16#70# 16#00#

.unalignedInitWord 0xcafe // ASM language

.ascii 16#0# // Name. DwarfLib expects this to be present.

.uleb128 0x2    ;# (DIE DW_TAG_subprogram)

// FUNCTION NAME GOES HERE. Use `echo name | od -t x1' to get the hex. Each hex

// digit is specified using the format 16#XX#

.ascii 16#5f# 16#75# 16#64# 16#69# 16#76# 16#6d# 16#6f# 16#64# 16#73# 16#69# 16#34# 16#0# // Function name `_udivmodsi4'

.unalignedInitWord _picoMark_FUNCTION_BEGIN     // DW_AT_low_pc

.unalignedInitWord _picoMark_FUNCTION_END       // DW_AT_high_pc

.initByte 0x0   // end of compile unit children.

_picoMark_DEBUG_INFO_END=

//============================================================================

// END OF DWARF

//============================================================================

.section .endFile

// End of picoChip ASM file