Re: [PATCH 3/5] powerpc/lib/sstep: Add bpermd instruction emulation
From: Gabriel Paubert <hidden>
Date: 2017-07-13 07:27:56
On Thu, Jul 13, 2017 at 01:25:46PM +1000, Matt Brown wrote:
quoted hunk ↗ jump to hunk
This adds emulation for the bpermd instruction. Signed-off-by: Matt Brown <redacted> --- arch/powerpc/lib/sstep.c | 23 +++++++++++++++++++++++ 1 file changed, 23 insertions(+)diff --git a/arch/powerpc/lib/sstep.c b/arch/powerpc/lib/sstep.c index cf69987..603654d 100644 --- a/arch/powerpc/lib/sstep.c +++ b/arch/powerpc/lib/sstep.c@@ -637,6 +637,21 @@ static nokprobe_inline void do_popcnt(struct pt_regs *regs, unsigned long v1, regs->gpr[ra] = out_val; } +static nokprobe_inline void do_bpermd(struct pt_regs *regs, unsigned long v1, + unsigned long v2, int ra) +{ + unsigned int idx, i; + unsigned char perm; + + perm = 0x0; + for (i = 0; i < 8; i++) { + idx = (v1 >> (i * 8)) & 0xff; + if (idx < 64) + perm |= (v2 & (1 << idx)) >> (idx - i); + } + regs->gpr[ra] = 0 | perm;
Huh? What's the point of doing an or with 0? The compiler will eliminate it, but it just confuses the reader. Gabriel
quoted hunk ↗ jump to hunk
+} + static nokprobe_inline int trap_compare(long v1, long v2) { int ret = 0;@@ -1274,6 +1289,14 @@ int analyse_instr(struct instruction_op *op, struct pt_regs *regs, goto logical_done; #endif +#ifdef __powerpc64__ + case 2396736: /* bpermd */ + val = regs->gpr[rd]; + val2 = regs->gpr[rb]; + do_bpermd(regs, val, val2, ra); + goto logical_done; +#endif + /* * Shift instructions */-- 2.9.3