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[/] [openrisc/] [trunk/] [or1ksim/] [testsuite/] [test-code-or1k/] [inst-set-test/] [is-sub-test.S] - Blame information for rev 538

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1 124 jeremybenn
/* is-sub-test.S. l.sub instruction test of Or1ksim
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 *
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 * Copyright (C) 1999-2006 OpenCores
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 * Copyright (C) 2010 Embecosm Limited
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 *
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 * Contributors various OpenCores participants
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 * Contributor Jeremy Bennett 
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 *
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 * This file is part of OpenRISC 1000 Architectural Simulator.
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 *
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 * This program is free software; you can redistribute it and/or modify it
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 * under the terms of the GNU General Public License as published by the Free
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 * Software Foundation; either version 3 of the License, or (at your option)
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 * any later version.
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 *
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 * This program is distributed in the hope that it will be useful, but WITHOUT
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 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
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 * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
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 * more details.
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 *
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 * You should have received a copy of the GNU General Public License along
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 * with this program.  If not, see .
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 */
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/* ----------------------------------------------------------------------------
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 * Coding conventions are described in inst-set-test.S
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 * ------------------------------------------------------------------------- */
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/* ----------------------------------------------------------------------------
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 * Test coverage
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 *
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 * The l.sub instruction should set the carry and overflow flags.
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 *
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 * Problems in this area were reported in Bugs 1782, 1783 and 1784. Having
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 * fixed the problem, this is (in good software engineering style), a
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 * regression test to go with the fix.
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 *
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 * This is not a comprehensive test of any instruction (yet).
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 *
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 * Of course what is really needed is a comprehensive instruction test...
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 * ------------------------------------------------------------------------- */
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#include "inst-set-test.h"
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/* ----------------------------------------------------------------------------
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 * A macro to carry out a test of subtraction in registers
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 *
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 *
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 * Arguments
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 *   set_flags: Flags to set in the SR
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 *   clr_flags: Flags to clear in the SR
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 *   op1:       First operand value
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 *   op2:       Second operand value
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 *   res:       Expected result
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 *   cy:        Expected carry flag
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 *   ov:        Expected overflow flag
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 * ------------------------------------------------------------------------- */
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#define TEST_SUB(set_flags, clr_flags, op1, op2, res, cy, ov)            \
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        l.mfspr r3,r0,SPR_SR                                            ;\
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        LOAD_CONST (r2, set_flags)      /* Set flags */                 ;\
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        l.or    r3,r3,r2                                                ;\
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        LOAD_CONST (r2, ~clr_flags)     /* Clear flags */               ;\
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        l.and   r3,r3,r2                                                ;\
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        l.mtspr r0,r3,SPR_SR                                            ;\
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                                                                        ;\
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        LOAD_CONST (r5,op1)             /* Load numbers to subtract */  ;\
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        LOAD_CONST (r6,op2)                                             ;\
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        l.mtspr r0,r0,SPR_EPCR_BASE     /* Clear record */              ;\
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50:     l.sub   r4,r5,r6                                                ;\
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        l.mfspr r2,r0,SPR_SR            /* So we can examine flags */   ;\
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        l.mfspr r5,r0,SPR_EPCR_BASE     /* What triggered exception */  ;\
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        PUSH (r5)                       /* Save EPCR for later */       ;\
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        PUSH (r2)                                                       ;\
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        PUSH (r4)                       /* Save result for later */     ;\
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                                                                        ;\
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        PUTS ("  0x")                                                   ;\
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        PUTH (op1)                                                      ;\
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        PUTS (" - 0x")                                                  ;\
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        PUTH (op2)                                                      ;\
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        PUTS (" = 0x")                                                  ;\
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        PUTH (res)                                                      ;\
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        PUTS (": ")                                                     ;\
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        POP (r4)                                                        ;\
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        CHECK_RES1 (r4, res)                                            ;\
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                                                                        ;\
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        POP(r2)                         /* Retrieve SR */               ;\
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        PUSH(r2)                                                        ;\
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        LOAD_CONST (r4, SPR_SR_CY)      /* The carry bit */             ;\
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        l.and   r2,r2,r4                                                ;\
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        l.sfeq  r2,r4                                                   ;\
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        CHECK_FLAG ("- carry flag set:      ", cy)                      ;\
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                                                                        ;\
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        POP(r2)                         /* Retrieve SR */               ;\
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        LOAD_CONST (r4, SPR_SR_OV)      /* The overflow bit */          ;\
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        l.and   r2,r2,r4                                                ;\
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        l.sfeq  r2,r4                                                   ;\
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        CHECK_FLAG ("- overflow flag set:   ", ov)                      ;\
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                                                                        ;\
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        POP (r2)                        /* Retrieve EPCR */             ;\
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        LOAD_CONST (r4, 50b)            /* The opcode of interest */    ;\
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        l.and   r2,r2,r4                                                ;\
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        l.sfeq  r2,r4                                                   ;\
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        l.bnf   53f                                                     ;\
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                                                                        ;\
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        PUTS ("  - exception triggered: TRUE\n")                        ;\
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        l.j     54f                                                     ;\
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        l.nop                                                           ;\
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                                                                        ;\
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53:     PUTS ("  - exception triggered: FALSE\n")                       ;\
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54:
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/* ----------------------------------------------------------------------------
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 * Start of code
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 * ------------------------------------------------------------------------- */
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        .section .text
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        .global _start
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_start:
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        l.mfspr r3,r0,SPR_SR
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        LOAD_CONST (r2, ~SPR_SR_OVE)    /* Clear OVE */
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        l.and   r3,r3,r2
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        l.mtspr r0,r3,SPR_SR
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        LOAD_STR (r3, "  ** OVE flag cleared **\n")
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        l.jal   _puts
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        l.nop
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/* ----------------------------------------------------------------------------
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 * Test of subtract signed, l.sub
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 * ------------------------------------------------------------------------- */
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_sub:
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        LOAD_STR (r3, "l.sub\n")
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        l.jal   _puts
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        l.nop
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        /* Subtract two small positive numbers. Sets the carry, but never the
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           overflow if the result is negative. */
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        TEST_SUB (0, SPR_SR_CY | SPR_SR_OV,
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                  0x00000003, 0x00000002, 0x00000001,
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                  FALSE, FALSE)
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        TEST_SUB (0, SPR_SR_CY | SPR_SR_OV,
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                  0x00000001, 0x00000002, 0xffffffff,
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                  TRUE, FALSE)
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        /* Check carry in is ignored. */
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        TEST_SUB (SPR_SR_CY, SPR_SR_OV,
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                  0x00000003, 0x00000002, 0x00000001,
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                  FALSE, FALSE)
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        /* Subtract two small negative numbers. Sets the carry flag if the
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           result is negative, but never the overflow flag. */
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        TEST_SUB (0, SPR_SR_CY | SPR_SR_OV,
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                  0xfffffffd, 0xfffffffe, 0xffffffff,
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                  TRUE, FALSE)
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        TEST_SUB (0, SPR_SR_CY | SPR_SR_OV,
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                  0xffffffff, 0xfffffffe, 0x00000001,
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                  FALSE, FALSE)
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        /* Subtract two quite large positive numbers. Should set neither the
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           overflow nor the carry flag. */
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        TEST_SUB (0, SPR_SR_CY | SPR_SR_OV,
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                  0x7fffffff, 0x3fffffff, 0x40000000,
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                  FALSE, FALSE)
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        /* Subtract two quite large negative numbers. Should set neither the
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           overflow nor the carry flag. */
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        TEST_SUB (0, SPR_SR_CY | SPR_SR_OV,
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                  0x40000000, 0x40000000, 0x00000000,
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                  FALSE, FALSE)
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        /* Subtract two large positive numbers with a negative result. Should
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           set the carry, but not the overflow flag. */
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        TEST_SUB (0, SPR_SR_CY | SPR_SR_OV,
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                  0x3fffffff, 0x40000000, 0xffffffff,
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                  TRUE, FALSE)
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        /* Subtract two large negative numbers with a positive result. Should
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           set niether the carry nor the overflow flag. */
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        TEST_SUB (0, SPR_SR_CY | SPR_SR_OV,
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                  0x40000000, 0x3fffffff, 0x00000001,
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                  FALSE, FALSE)
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        /* Subtract a large positive from a large negative number. Should set
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           overflow but not the carry flag. */
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        TEST_SUB (0, SPR_SR_CY | SPR_SR_OV,
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                  0x80000000, 0x7fffffff, 0x00000001,
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                  FALSE, TRUE)
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        /* Subtract a large negative from a large positive number. Should set
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           both the overflow and carry flags. */
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        TEST_SUB (0, SPR_SR_CY | SPR_SR_OV,
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                  0x7fffffff, 0x80000000, 0xffffffff,
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                  TRUE, TRUE)
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        /* Check that range exceptions are triggered */
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        l.mfspr r3,r0,SPR_SR
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        LOAD_CONST (r2, SPR_SR_OVE)     /* Set OVE */
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        l.or    r3,r3,r2
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        l.mtspr r0,r3,SPR_SR
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        LOAD_STR (r3, "  ** OVE flag set **\n")
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        l.jal   _puts
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        l.nop
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        /* Check that an overflow alone causes a RANGE Exception. */
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        TEST_SUB (0, SPR_SR_CY | SPR_SR_OV,
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                  0x80000000, 0x7fffffff, 0x00000001,
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                  FALSE, TRUE)
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        /* Check that a carry alone does not cause a RANGE Exception. */
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        TEST_SUB (0, SPR_SR_CY | SPR_SR_OV,
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                  0x3fffffff, 0x40000000, 0xffffffff,
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                  TRUE, FALSE)
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        /* Check that carry and overflow together cause an exception. */
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        TEST_SUB (0, SPR_SR_CY | SPR_SR_OV,
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                  0x7fffffff, 0x80000000, 0xffffffff,
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                  TRUE, TRUE)
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        /* Finished checking range exceptions */
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        l.mfspr r3,r0,SPR_SR
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        LOAD_CONST (r2, ~SPR_SR_OVE)    /* Clear OVE */
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        l.and   r3,r3,r2
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        l.mtspr r0,r3,SPR_SR
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        LOAD_STR (r3, "  ** OVE flag cleared **\n")
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        l.jal   _puts
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        l.nop
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/* ----------------------------------------------------------------------------
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 * All done
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 * ------------------------------------------------------------------------- */
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_exit:
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        LOAD_STR (r3, "Test completed\n")
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        l.jal   _puts
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        l.nop
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        TEST_EXIT

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