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| author | Samuel Thibault <samuel.thibault@ens-lyon.org> | 2024-12-09 22:23:10 +0100 |
|---|---|---|
| committer | Samuel Thibault <samuel.thibault@ens-lyon.org> | 2024-12-09 22:23:10 +0100 |
| commit | 39c64a75878480ca96b2ed61d89c51c199ade21a (patch) | |
| tree | 9786ecb65a05866a426b775bfce6bf75ad8f58d9 | |
| parent | ae3597fe2e07bae7dea9cd6278a0fcf7dbb1df7b (diff) | |
| download | gnumach-39c64a75878480ca96b2ed61d89c51c199ade21a.tar.gz gnumach-39c64a75878480ca96b2ed61d89c51c199ade21a.tar.bz2 gnumach-39c64a75878480ca96b2ed61d89c51c199ade21a.zip | |
Comment on the reason for the different CPU_NUMBER versions
| -rw-r--r-- | i386/i386/cpu_number.h | 3 |
1 files changed, 3 insertions, 0 deletions
diff --git a/i386/i386/cpu_number.h b/i386/i386/cpu_number.h index 67c19e9b..547e0498 100644 --- a/i386/i386/cpu_number.h +++ b/i386/i386/cpu_number.h @@ -41,12 +41,14 @@ #define CX(addr, reg) addr(,reg,8) #endif +/* Slow version, always works */ #define CPU_NUMBER_NO_STACK(reg) \ movl %cs:lapic, reg ;\ movl %cs:APIC_ID(reg), reg ;\ shrl $24, reg ;\ movl %cs:CX(cpu_id_lut, reg), reg ;\ +/* Fast version, requires a stack */ #ifdef __i386__ /* Never call CPU_NUMBER_NO_GS(%esi) */ #define CPU_NUMBER_NO_GS(reg) \ @@ -86,6 +88,7 @@ popq %rsi #endif +/* Fastest version, requires gs being set up */ #define CPU_NUMBER(reg) \ movl MY(CPU_ID), reg; |