From: Matt Brown <matthew.brown.dev@gmail.com>
To: linuxppc-dev@lists.ozlabs.org
Cc: anton@samba.org
Subject: [PATCH 2/5] powerpc/lib/sstep: Add popcnt instruction emulation
Date: Thu, 13 Jul 2017 13:25:45 +1000 [thread overview]
Message-ID: <20170713032548.451-2-matthew.brown.dev@gmail.com> (raw)
In-Reply-To: <20170713032548.451-1-matthew.brown.dev@gmail.com>
This adds emulations for the popcntb, popcntw, and popcntd instructions.
Signed-off-by: Matt Brown <matthew.brown.dev@gmail.com>
---
arch/powerpc/lib/sstep.c | 39 +++++++++++++++++++++++++++++++++++++++
1 file changed, 39 insertions(+)
diff --git a/arch/powerpc/lib/sstep.c b/arch/powerpc/lib/sstep.c
index f3e9ba8..cf69987 100644
--- a/arch/powerpc/lib/sstep.c
+++ b/arch/powerpc/lib/sstep.c
@@ -613,6 +613,30 @@ static nokprobe_inline void do_cmpb(struct pt_regs *regs, unsigned long v1,
regs->gpr[rd] = out_val;
}
+/*
+ * The size parameter is used to ajust the equivalent popcnt instruction.
+ * popcntb = 8, popcntw = 32, popcntd = 64
+ */
+static nokprobe_inline void do_popcnt(struct pt_regs *regs, unsigned long v1,
+ int size, int ra)
+{
+ unsigned int out_val, mask, n;
+ int i, j;
+
+ out_val = 0;
+
+ for (i = 0; i < (64 / size); i++) {
+ n = 0;
+ for (j = 0; j < size; j++) {
+ mask = 1 << (j + (i * size));
+ if (v1 & mask)
+ n++;
+ }
+ out_val |= n << (i * size);
+ }
+ regs->gpr[ra] = out_val;
+}
+
static nokprobe_inline int trap_compare(long v1, long v2)
{
int ret = 0;
@@ -1234,6 +1258,21 @@ int analyse_instr(struct instruction_op *op, struct pt_regs *regs,
regs->gpr[ra] = (signed int) regs->gpr[rd];
goto logical_done;
#endif
+ case 299528: /* popcntb */
+ val = regs->gpr[rd];
+ do_popcnt(regs, val, 8, ra);
+ goto logical_done;
+
+ case 17076744: /* popcntw */
+ val = regs->gpr[rd];
+ do_popcnt(regs, val, 32, ra);
+ goto logical_done;
+#ifdef __powerpc64__
+ case 19173896: /* popcntd */
+ val = regs->gpr[rd];
+ do_popcnt(regs, val, 64, ra);
+ goto logical_done;
+#endif
/*
* Shift instructions
--
2.9.3
next prev parent reply other threads:[~2017-07-13 3:26 UTC|newest]
Thread overview: 18+ messages / expand[flat|nested] mbox.gz Atom feed top
2017-07-13 3:25 [PATCH 1/5] powerpc/lib/sstep: Add cmpb instruction emulation Matt Brown
2017-07-13 3:25 ` Matt Brown [this message]
2017-07-13 3:25 ` [PATCH 3/5] powerpc/lib/sstep: Add bpermd " Matt Brown
2017-07-13 7:16 ` Gabriel Paubert
2017-07-13 7:28 ` Segher Boessenkool
2017-07-14 4:19 ` Matt Brown
2017-07-14 16:17 ` Segher Boessenkool
2017-07-13 3:25 ` [PATCH 4/5] powerpc/lib/sstep: Add prty " Matt Brown
2017-07-13 7:37 ` Segher Boessenkool
2017-07-14 0:46 ` Matt Brown
2017-07-14 19:02 ` kbuild test robot
2017-07-13 3:25 ` [PATCH 5/5] powerpc/lib/sstep: Add isel " Matt Brown
2017-07-13 7:47 ` Segher Boessenkool
2017-07-14 0:49 ` Matt Brown
2017-07-13 3:51 ` [PATCH 1/5] powerpc/lib/sstep: Add cmpb " Andrew Donnellan
2017-07-13 6:43 ` Segher Boessenkool
2017-07-13 7:10 ` Segher Boessenkool
2017-07-13 6:46 ` Segher Boessenkool
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