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| author | Ali Saidi <saidi@eecs.umich.edu> | 2004-06-06 19:33:50 -0400 |
|---|---|---|
| committer | Ali Saidi <saidi@eecs.umich.edu> | 2004-06-06 19:33:50 -0400 |
| commit | ea03f8e35d418d810036fe23c43e6060f74f2541 (patch) | |
| tree | 9ac0d2c660a3514fc08cd7643534218f6ac9deb3 /system | |
| parent | 120825c1e2c0d1fac57f3692ae7fe3194fbd0b3c (diff) | |
| download | gem5-ea03f8e35d418d810036fe23c43e6060f74f2541.tar.xz | |
Rather than using a loop to calculate the interrupt vector, use the ctlz instruction.
Diffstat (limited to 'system')
| -rw-r--r-- | system/alpha/palcode/platform_m5.s | 31 |
1 files changed, 7 insertions, 24 deletions
diff --git a/system/alpha/palcode/platform_m5.s b/system/alpha/palcode/platform_m5.s index 7e068b100..9012fd79e 100644 --- a/system/alpha/palcode/platform_m5.s +++ b/system/alpha/palcode/platform_m5.s @@ -839,39 +839,22 @@ sys_int_21: bis r8,r9,r8 ldqp r9,0x0020(r8) // read PIC1 ISR for interrupting dev -#if 0 // we have a 21164 so this won't work because of the ctlz, if we ever change that... normal_int: - ctlz r9,r10 // count the number of leading zeros + //ctlz r9,r10 // count the number of leading zeros + // EV5 doesn't have ctlz, but we do, so lets use it + .byte 0x4a + .byte 0x06 + .byte 0xe9 + .byte 0x73 lda r11,63(r31) subq r11,r10,r17 // subtract from lda r9,0x10(r31) mulq r17,r9,r17 // compute 0x900 + (0x10 * Highest DIRn-bit) - lda r9,0x900(r31) - addq r17,r9,r17 - - br r31, pal_post_interrupt -#endif - -normal_int: - or r31,63,r17 // load 63 into the counter - or r31,1,r11 - sll r11,63,r11 // load a 1 into the msb - -find_msb: - and r9,r11,r10 - bne r10, found_msb - srl r11,1,r11 - subl r17,1,r17 - br r31, find_msb - -found_msb: - lda r9,0x10(r31) - mulq r17,r9,r17 // compute offset + (0x10 * Highest DIRn-bit) addq r17,r13,r17 br r31, pal_post_interrupt - + ALIGN_BRANCH pal_post_dev_interrupt: or r13, r31, r17 // move vector to a1 |