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/* is-mul-test.S. l.mul, l.muli and l.mulu instruction test of Or1ksim
 * 
 * Copyright (C) 1999-2006 OpenCores
 * Copyright (C) 2010 Embecosm Limited
 * 
 * Contributors various OpenCores participants
 * Contributor Jeremy Bennett <jeremy.bennett@embecosm.com>
 * 
 * This file is part of OpenRISC 1000 Architectural Simulator.
 * 
 * This program 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 of the License, or (at your option)
 * any later version.
 * 
 * This program 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.
 * 
 * You should have received a copy of the GNU General Public License along
 * with this program.  If not, see <http:  www.gnu.org/licenses/>.
 */

/* ----------------------------------------------------------------------------
 * Coding conventions are described in inst-set-test.S
 * ------------------------------------------------------------------------- */

/* ----------------------------------------------------------------------------
 * Test coverage
 *
 * The l.mul, l.muli and l.mulu instructions should all be present and set the
 * carry and overflow flags.
 *
 * Problems in this area were reported in Bugs 1774, 1782, 1783 and 1784.
 * Having fixed the problem, this is (in good software engineering style), a
 * regression test to go with the fix.
 *
 * This is not a comprehensive test of any instruction (yet).
 *
 * Of course what is really needed is a comprehensive instruction test...
 * ------------------------------------------------------------------------- */


#include "inst-set-test.h"

/* ----------------------------------------------------------------------------
 * A macro to carry out a test of multiply signed or unsigned
 *
 * Arguments
 *   opc:       The opcode
 *   op1:       First operand value
 *   op2:       Second operand value
 *   res:       Expected result
 *   cy:        Expected carry flag
 *   ov:        Expected overflow flag
 * ------------------------------------------------------------------------- */
#define TEST_MUL(opc, op1, op2, res, cy, ov)                             \
        l.mfspr r3,r0,SPR_SR                                            ;\
        LOAD_CONST (r2, ~(SPR_SR_CY | SPR_SR_OV))                       ;\
        l.and   r3,r3,r2                /* Clear flags */               ;\
        l.mtspr r0,r3,SPR_SR                                            ;\
                                                                        ;\
        LOAD_CONST (r5,op1)             /* Load numbers to add */       ;\
        LOAD_CONST (r6,op2)                                             ;\
        l.mtspr r0,r0,SPR_EPCR_BASE     /* Clear record */              ;\
50:     opc     r4,r5,r6                                                ;\
        l.mfspr r2,r0,SPR_SR            /* So we can examine flags */   ;\
        l.mfspr r5,r0,SPR_EPCR_BASE     /* What triggered exception */  ;\
        PUSH (r5)                       /* Save EPCR for later */       ;\
        PUSH (r2)                       /* Save SR for later */         ;\
        PUSH (r4)                       /* Save result for later */     ;\
                                                                        ;\
        PUTS ("  0x")                                                   ;\
        PUTH (op1)                                                      ;\
        PUTS (" * 0x")                                                  ;\
        PUTH (op2)                                                      ;\
        PUTS (" = 0x")                                                  ;\
        PUTH (res)                                                      ;\
        PUTS (": ")                                                     ;\
        POP (r4)                                                        ;\
        CHECK_RES1 (r4, res)                                            ;\
                                                                        ;\
        POP (r2)                        /* Retrieve SR */               ;\
        PUSH (r2)                                                       ;\
        LOAD_CONST (r4, SPR_SR_CY)      /* The carry bit */             ;\
        l.and   r2,r2,r4                                                ;\
        l.sfeq  r2,r4                                                   ;\
        CHECK_FLAG ("- carry flag set:      ", cy)                      ;\
                                                                        ;\
        POP (r2)                        /* Retrieve SR */               ;\
        LOAD_CONST (r4, SPR_SR_OV)      /* The overflow bit */          ;\
        l.and   r2,r2,r4                                                ;\
        l.sfeq  r2,r4                                                   ;\
        CHECK_FLAG ("- overflow flag set:   ", ov)                      ;\
                                                                        ;\
        POP (r2)                        /* Retrieve EPCR */             ;\
        LOAD_CONST (r4, 50b)            /* The opcode of interest */    ;\
        l.and   r2,r2,r4                                                ;\
        l.sfeq  r2,r4                                                   ;\
        l.bnf   51f                                                     ;\
                                                                        ;\
        PUTS ("  - exception triggered: TRUE\n")                        ;\
        l.j     52f                                                     ;\
        l.nop                                                           ;\
                                                                        ;\
51:     PUTS ("  - exception triggered: FALSE\n")                       ;\
52:     
        
        
/* ----------------------------------------------------------------------------
 * A macro to carry out a test of multiply immediate
 *
 * Arguments
 *   op1:       First operand value
 *   op2:       Second operand value
 *   res:       Expected result
 *   cy:        Expected carry flag
 *   ov:        Expected overflow flag
 * ------------------------------------------------------------------------- */
#define TEST_MULI(op1, op2, res, cy, ov)                                 \
        l.mfspr r3,r0,SPR_SR                                            ;\
        LOAD_CONST (r2, ~(SPR_SR_CY | SPR_SR_OV))                       ;\
        l.and   r3,r3,r2                /* Clear flags */               ;\
        l.mtspr r0,r3,SPR_SR                                            ;\
                                                                        ;\
        LOAD_CONST (r5,op1)             /* Load numbers to add */       ;\
        l.mtspr r0,r0,SPR_EPCR_BASE     /* Clear record */              ;\
53:     l.muli  r4,r5,op2                                               ;\
        l.mfspr r2,r0,SPR_SR            /* So we can examine flags */   ;\
        l.mfspr r5,r0,SPR_EPCR_BASE     /* What triggered exception */  ;\
        PUSH (r5)                       /* Save EPCR for later */       ;\
        PUSH (r2)                       /* Save SR for later */         ;\
        PUSH (r4)                       /* Save result for later */     ;\
                                                                        ;\
        PUTS ("  0x")                                                   ;\
        PUTH (op1)                                                      ;\
        PUTS (" * 0x")                                                  ;\
        PUTHH (op2)                                                     ;\
        PUTS (" = 0x")                                                  ;\
        PUTH (res)                                                      ;\
        PUTS (": ")                                                     ;\
        POP (r4)                                                        ;\
        CHECK_RES1 (r4, res)                                            ;\
                                                                        ;\
        POP(r2)                         /* Retrieve SR */               ;\
        PUSH(r2)                                                        ;\
        LOAD_CONST (r4, SPR_SR_CY)      /* The carry bit */             ;\
        l.and   r2,r2,r4                                                ;\
        l.sfeq  r2,r4                                                   ;\
        CHECK_FLAG ("- carry flag set:      ", cy)                      ;\
                                                                        ;\
        POP(r2)                         /* Retrieve SR */               ;\
        LOAD_CONST (r4, SPR_SR_OV)      /* The overflow bit */          ;\
        l.and   r2,r2,r4                                                ;\
        l.sfeq  r2,r4                                                   ;\
        CHECK_FLAG ("- overflow flag set:   ", ov)                      ;\
                                                                        ;\
        POP (r2)                        /* Retrieve EPCR */             ;\
        LOAD_CONST (r4, 53b)            /* The opcode of interest */    ;\
        l.and   r2,r2,r4                                                ;\
        l.sfeq  r2,r4                                                   ;\
        l.bnf   54f                                                     ;\
                                                                        ;\
        PUTS ("  - exception triggered: TRUE\n")                        ;\
        l.j     55f                                                     ;\
        l.nop                                                           ;\
                                                                        ;\
54:     PUTS ("  - exception triggered: FALSE\n")                       ;\
55:     
        

/* ----------------------------------------------------------------------------
 * Start of code
 * ------------------------------------------------------------------------- */
        .section .text
        .global _start
_start:
        l.mfspr r3,r0,SPR_SR
        LOAD_CONST (r2, ~SPR_SR_OVE)    /* Clear OVE */
        l.and   r3,r3,r2
        l.mtspr r0,r3,SPR_SR
        
        LOAD_STR (r3, "  ** OVE flag cleared **\n")
        l.jal   _puts
        l.nop

/* ----------------------------------------------------------------------------
 * Test of multiply signed, l.mul
 * ------------------------------------------------------------------------- */
_mul:
        LOAD_STR (r3, "l.mul\n")
        l.jal   _puts
        l.nop

        /* Multiply two small positive numbers. Should set no flags. */
        TEST_MUL (l.mul, 0x00000002, 0x00000003,
                  0x00000006, FALSE, FALSE)

        /* Multiply two quite large positive numbers. Should set no flags */
        TEST_MUL (l.mul, 0x00008001, 0x0000fffe,
                  0x7ffffffe, FALSE, FALSE)

        /* Multiply two slightly too large positive numbers. Should set the
           overflow, but not the carry flag */
        TEST_MUL (l.mul, 0x00008000, 0x00010000,
                  0x80000000, FALSE, TRUE)

        /* Multiply two large positive numbers. Should set both the carry and
           overflow flags (even though the result is not a negative number. */
        TEST_MUL (l.mul, 0x00010000, 0x00010000, 0x00000000, TRUE, TRUE)

        /* Multiply two small negative numbers. Should set the overflow, but not
           the carry flag. */
        TEST_MUL (l.mul, 0xfffffffe, 0xfffffffd,
                  0x00000006, TRUE, FALSE)

        /* Multiply two quite large negative numbers. Should set the overflow,
           but not the carry flag. */
        TEST_MUL (l.mul, 0xffff7fff, 0xffff0002,
                  0x7ffffffe, TRUE, FALSE)

        /* Multiply two slightly too large negative numbers. Should set both the
           overflow, and the carry flags */
        TEST_MUL (l.mul, 0xffff7fff, 0xffff0000,
                  0x80010000, TRUE, TRUE)

        /* Multiply two large negative numbers. Should set the
           both the carry and overflow flags (even though the result is a
           positive number. */
        TEST_MUL (l.mul, 0xffff0000, 0xfffeffff,
                  0x00010000, TRUE, TRUE)

        /* Multiply one small negative number and one small positive number.
           Should set the overflow, but not the carry flag. */
        TEST_MUL (l.mul, 0x00000002, 0xfffffffd,
                  0xfffffffa, TRUE, FALSE)

        /* Multiply one quite large negative number and one quite large
           positive number. Should set the overflow, but not the carry flag. */
        TEST_MUL (l.mul, 0xffff8000, 0x00010000,
                  0x80000000, TRUE, FALSE)

        /* Multiply one slightly too large negative number and one slightly
           too large positive number. Should set both the carry and overflow
           flags. */
        TEST_MUL (l.mul, 0xffff7fff, 0x00010000,
                  0x7fff0000, TRUE, TRUE)

        /* Multiply the largest negative number by positive unity. Should set
           neither carry, nor overflow flag. */
        TEST_MUL (l.mul, 0x80000000, 0x00000001,
                  0x80000000, FALSE, FALSE)

        /* Check that range exceptions are triggered */
        l.mfspr r3,r0,SPR_SR
        LOAD_CONST (r2, SPR_SR_OVE)     /* Set OVE */
        l.or    r3,r3,r2
        l.mtspr r0,r3,SPR_SR
        
        LOAD_STR (r3, "  ** OVE flag set **\n")
        l.jal   _puts
        l.nop

        /* Check that an overflow alone causes a RANGE Exception. */
        TEST_MUL (l.mul, 0x00008000, 0x00010000,
                  0x80000000, FALSE, TRUE)

        /* Check that a carry alone does not cause a RANGE Exception. */
        TEST_MUL (l.mul, 0x00000002, 0xfffffffd,
                  0xfffffffa, TRUE, FALSE)

        /* Check that carry and overflow together cause an exception. */
        TEST_MUL (l.mul, 0xffff7fff, 0xffff0000,
                  0x80010000, TRUE, TRUE)

        /* Finished checking range exceptions */
        l.mfspr r3,r0,SPR_SR
        LOAD_CONST (r2, ~SPR_SR_OVE)    /* Clear OVE */
        l.and   r3,r3,r2
        l.mtspr r0,r3,SPR_SR
        
        LOAD_STR (r3, "  ** OVE flag cleared **\n")
        l.jal   _puts
        l.nop

/* ----------------------------------------------------------------------------
 * Test of multiply signed, l.muli
 * ------------------------------------------------------------------------- */
_muli:
        LOAD_STR (r3, "l.muli\n")
        l.jal   _puts
        l.nop

        /* Multiply two small positive numbers. Should set no flags. */
        TEST_MULI (0x00000002, 0x0003,
                  0x00000006, FALSE, FALSE)

        /* Multiply two quite large positive numbers. Should set no flags */
        TEST_MULI (0x00010002, 0x7fff,
                  0x7ffffffe, FALSE, FALSE)

        /* Multiply two slightly too large positive numbers. Should set the
           overflow, but not the carry flag */
        TEST_MULI (0x00020000, 0x4000,
                  0x80000000, FALSE, TRUE)

        /* Multiply two large positive numbers. Should set both the carry and
           overflow flags (even though the result is not a negative number. */
        TEST_MULI (0x00040000, 0x4000,
                   0x00000000, TRUE, TRUE)

        /* Multiply two small negative numbers. Should set the overflow, but not
           the carry flag. */
        TEST_MULI (0xfffffffe, 0xfffd,
                  0x00000006, TRUE, FALSE)

        /* Multiply two quite large negative numbers. Should set the overflow,
           but not the carry flag. */
        TEST_MULI (0xfffefffe, 0x8001,
                  0x7ffffffe, TRUE, FALSE)

        /* Multiply two slightly too large negative numbers. Should set both the
           overflow, and the carry flags */
        TEST_MULI (0xfffe0000, 0xbfff,
                  0x80020000, TRUE, TRUE)

        /* Multiply two large negative numbers. Should set the
           both the carry and overflow flags (even though the result is a
           positive number. */
        TEST_MULI (0xfffdfffe, 0x8000,
                  0x00010000, TRUE, TRUE)

        /* Multiply one small negative number and one small positive number.
           Should set the overflow, but not the carry flag. */
        TEST_MULI (0x00000002, 0xfffd,
                  0xfffffffa, TRUE, FALSE)

        /* Multiply one quite large negative number and one quite large
           positive number. Should set the overflow, but not the carry flag. */
        TEST_MULI (0x00010000, 0x8000,
                  0x80000000, TRUE, FALSE)

        /* Multiply one slightly too large negative number and one slightly
           too large positive number. Should set both the carry and overflow
           flags. */
        TEST_MULI (0xfffdfffc, 0x4000,
                  0x7fff0000, TRUE, TRUE)

        /* Multiply the largest negative number by positive unity. Should set
           neither carry, nor overflow flag. */
        TEST_MULI (0x80000000, 0x0001,
                  0x80000000, FALSE, FALSE)

        /* Check that range exceptions are triggered */
        l.mfspr r3,r0,SPR_SR
        LOAD_CONST (r2, SPR_SR_OVE)     /* Set OVE */
        l.or    r3,r3,r2
        l.mtspr r0,r3,SPR_SR
        
        LOAD_STR (r3, "  ** OVE flag set **\n")
        l.jal   _puts
        l.nop

        /* Check that an overflow alone causes a RANGE Exception. */
        TEST_MULI (0x00020000, 0x4000,
                  0x80000000, FALSE, TRUE)

        /* Check that a carry alone does not cause a RANGE Exception. */
        TEST_MULI (0xfffffffe, 0xfffd,
                  0x00000006, TRUE, FALSE)

        /* Check that carry and overflow together cause an exception. */
        TEST_MULI (0xfffdfffe, 0x8000,
                  0x00010000, TRUE, TRUE)

        /* Finished checking range exceptions */
        l.mfspr r3,r0,SPR_SR
        LOAD_CONST (r2, ~SPR_SR_OVE)    /* Clear OVE */
        l.and   r3,r3,r2
        l.mtspr r0,r3,SPR_SR
        
        LOAD_STR (r3, "  ** OVE flag cleared **\n")
        l.jal   _puts
        l.nop

/* ----------------------------------------------------------------------------
 * Test of multiply unsigned, l.mulu
 * ------------------------------------------------------------------------- */
_mulu:
        LOAD_STR (r3, "l.mulu\n")
        l.jal   _puts
        l.nop

        /* Multiply two small positive numbers. Should set no flags. */
        TEST_MUL (l.mulu, 0x00000002, 0x00000003,
                  0x00000006, FALSE, FALSE)

        /* Multiply two quite large positive numbers. Should set no flags */
        TEST_MUL (l.mulu, 0x00008001, 0x0000fffe,
                  0x7ffffffe, FALSE, FALSE)

        /* Multiply two slightly too large positive numbers. Should set the
           overflow, but not the carry flag */
        TEST_MUL (l.mulu, 0x00008000, 0x00010000,
                  0x80000000, FALSE, FALSE)

        /* Multiply two large positive numbers. Should set both the carry and
           overflow flags (even though the result is not a negative number. */
        TEST_MUL (l.mulu, 0x00010000, 0x00010000,
                  0x00000000, TRUE, FALSE)

        /* Multiply two small negative numbers. Should set the overflow, but not
           the carry flag. */
        TEST_MUL (l.mulu, 0xfffffffe, 0xfffffffd,
                  0x00000006, TRUE, FALSE)

        /* Multiply two quite large negative numbers. Should set the overflow,
           but not the carry flag. */
        TEST_MUL (l.mulu, 0xffff7fff, 0xffff0002,
                  0x7ffffffe, TRUE, FALSE)

        /* Multiply two slightly too large negative numbers. Should set both the
           overflow, and the carry flags */
        TEST_MUL (l.mulu, 0xffff7fff, 0xffff0000,
                  0x80010000, TRUE, FALSE)

        /* Multiply two large negative numbers. Should set the
           both the carry and overflow flags (even though the result is a
           positive number. */
        TEST_MUL (l.mulu, 0xffff0000, 0xfffeffff,
                  0x00010000, TRUE, FALSE)

        /* Multiply one small negative number and one small positive number.
           Should set the overflow, but not the carry flag. */
        TEST_MUL (l.mulu, 0x00000002, 0xfffffffd,
                  0xfffffffa, TRUE, FALSE)

        /* Multiply one quite large negative number and one quite large
           positive number. Should set the overflow, but not the carry flag. */
        TEST_MUL (l.mulu, 0xffff8000, 0x00010000,
                  0x80000000, TRUE, FALSE)

        /* Multiply one slightly too large negative number and one slightly
           too large positive number. Should set both the carry and overflow
           flags. */
        TEST_MUL (l.mulu, 0xffff7fff, 0x00010000,
                  0x7fff0000, TRUE, FALSE)

        /* Multiply the largest negative number by positive unity. Should set
           neither carry, nor overflow flag. */
        TEST_MUL (l.mulu, 0x80000000, 0x00000001,
                  0x80000000, FALSE, FALSE)

        /* Check that range exceptions are never triggered */
        l.mfspr r3,r0,SPR_SR
        LOAD_CONST (r2, SPR_SR_OVE)     /* Set OVE */
        l.or    r3,r3,r2
        l.mtspr r0,r3,SPR_SR
        
        LOAD_STR (r3, "  ** OVE flag set **\n")
        l.jal   _puts
        l.nop

        /* Check that what would cause an overflow alone in 2's complement does
           not cause a RANGE Exception. */
        TEST_MUL (l.mulu, 0x00008000, 0x00010000,
                  0x80000000, FALSE, FALSE)

        /* Check that a carry alone does not cause a RANGE Exception. */
        TEST_MUL (l.mulu, 0x00000002, 0xfffffffd,
                  0xfffffffa, TRUE, FALSE)

        /* Check that what would cause an overflow and carry in 2's complement
           does not cause a RANGE Exception. */
        TEST_MUL (l.mulu, 0xffff7fff, 0xffff0000,
                  0x80010000, TRUE, FALSE)

        /* Finished checking range exceptions */
        l.mfspr r3,r0,SPR_SR
        LOAD_CONST (r2, ~SPR_SR_OVE)    /* Clear OVE */
        l.and   r3,r3,r2
        l.mtspr r0,r3,SPR_SR
        
        LOAD_STR (r3, "  ** OVE flag cleared **\n")
        l.jal   _puts
        l.nop

/* ----------------------------------------------------------------------------
 * All done
 * ------------------------------------------------------------------------- */
_exit:
        LOAD_STR (r3, "Test completed\n")
        l.jal   _puts
        l.nop

        TEST_EXIT