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| author | Christian Krinitsin <mail@krinitsin.com> | 2025-05-30 16:52:07 +0200 |
|---|---|---|
| committer | Christian Krinitsin <mail@krinitsin.com> | 2025-05-30 16:52:17 +0200 |
| commit | 9260319e7411ff8281700a532caa436f40120ec4 (patch) | |
| tree | 2f6bfe5f3458dd49d328d3a9eb508595450adec0 /gitlab/issues_text/target_sh4/host_missing/accel_missing/2317 | |
| parent | 225caa38269323af1bfc2daadff5ec8bd930747f (diff) | |
| download | qemu-analysis-9260319e7411ff8281700a532caa436f40120ec4.tar.gz qemu-analysis-9260319e7411ff8281700a532caa436f40120ec4.zip | |
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Diffstat (limited to 'gitlab/issues_text/target_sh4/host_missing/accel_missing/2317')
| -rw-r--r-- | gitlab/issues_text/target_sh4/host_missing/accel_missing/2317 | 38 |
1 files changed, 38 insertions, 0 deletions
diff --git a/gitlab/issues_text/target_sh4/host_missing/accel_missing/2317 b/gitlab/issues_text/target_sh4/host_missing/accel_missing/2317 new file mode 100644 index 000000000..920b01b62 --- /dev/null +++ b/gitlab/issues_text/target_sh4/host_missing/accel_missing/2317 @@ -0,0 +1,38 @@ +SH4: ADDV instruction not emulated properly +Description of problem: +ADDV opcode is emulated incorrectly. + +The documentation says: + +`ADDV Rm, Rn Rn + Rm -> Rn, overflow -> T` + +What Qemu actually emulates: + +`ADDV Rm, Rn Rn + Rm -> Rm, overflow -> T` +Steps to reproduce: +```c +#include <stdio.h> + +int main(void) +{ + register unsigned int a asm("r8") = 0x7fffffff; + register unsigned int b asm("r9") = 1; + register unsigned int c asm("r10"); + + asm volatile("clrt\n" + "addv %2,%0\n" + "movt %1\n" + : "+r"(a), "=r"(c) : "r"(b) :); + + printf("Values: a=0x%x b=0x%x c=0x%x\n", a, b, c); + + return 0; +} + +``` +Additional information: +Tested on real hardware (SEGA Dreamcast, GCC 15.0), the program above prints: +`Values: a=0x80000000 b=0x1 c=0x1` + +Running with Qemu (and GCC 13.0), the same program prints: +`Values: a=0x7fffffff b=0x80000000 c=0x1` |