d0ce7e9cfc
The value of CCOUNT special register is calculated as time elapsed since CCOUNT == 0 multiplied by the core frequency. In icount mode time increment between consecutive instructions that don't involve time warps is constant, but unless the result of multiplication of this constant by the core frequency is a whole number the CCOUNT increment between these instructions may not be constant. E.g. with icount=7 each instruction takes 128ns, with core clock of 10MHz CCOUNT values for consecutive instructions are: 502: (128 * 502 * 10000000) / 1000000000 = 642.56 503: (128 * 503 * 10000000) / 1000000000 = 643.84 504: (128 * 504 * 10000000) / 1000000000 = 645.12 I.e.the CCOUNT increments depend on the absolute time. This results in varying CCOUNT differences for consecutive instructions in tests that involve time warps and don't set CCOUNT explicitly. Change frequency of the core used in tests so that clock cycle takes exactly 64ns. Change icount power used in tests to 6, so that each instruction takes exactly 1 clock cycle. With these changes CCOUNT increments only depend on the number of executed instructions and that's what timer tests expect, so they work correctly. Longer story: http://lists.nongnu.org/archive/html/qemu-devel/2018-03/msg04326.html Cc: Pavel Dovgaluk <Pavel.Dovgaluk@ispras.ru> Cc: Philippe Mathieu-Daudé <f4bug@amsat.org> Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org> Signed-off-by: Max Filippov <jcmvbkbc@gmail.com> |
||
|---|---|---|
| .. | ||
| alpha | ||
| cris | ||
| lm32 | ||
| mips | ||
| openrisc | ||
| xtensa | ||
| Makefile | ||
| README | ||
| hello-arm.c | ||
| hello-i386.c | ||
| hello-mips.c | ||
| linux-test.c | ||
| pi_10.com | ||
| runcom.c | ||
| sha1.c | ||
| test-arm-iwmmxt.s | ||
| test-i386-code16.S | ||
| test-i386-fprem.c | ||
| test-i386-muldiv.h | ||
| test-i386-shift.h | ||
| test-i386-ssse3.c | ||
| test-i386-vm86.S | ||
| test-i386.c | ||
| test-i386.h | ||
| test-mmap.c | ||
| test_path.c | ||
| testthread.c | ||
README
This directory contains various interesting programs for regression testing. The target "make test" runs the programs and, if applicable, runs "diff" to detect mismatches between output on the host and output on QEMU. i386 ==== test-i386 --------- This program executes most of the 16 bit and 32 bit x86 instructions and generates a text output, for comparison with the output obtained with a real CPU or another emulator. The Linux system call modify_ldt() is used to create x86 selectors to test some 16 bit addressing and 32 bit with segmentation cases. The Linux system call vm86() is used to test vm86 emulation. Various exceptions are raised to test most of the x86 user space exception reporting. linux-test ---------- This program tests various Linux system calls. It is used to verify that the system call parameters are correctly converted between target and host CPUs. test-i386-fprem --------------- runcom ------ test-mmap --------- sha1 ---- hello-i386 ---------- ARM === hello-arm --------- test-arm-iwmmxt --------------- MIPS ==== hello-mips ---------- hello-mipsel ------------ CRIS ==== The testsuite for CRIS is in tests/tcg/cris. You can run it with "make test-cris". LM32 ==== The testsuite for LM32 is in tests/tcg/cris. You can run it with "make test-lm32".