This adds emulation for the isel instruction.
Tested for correctness against the isel instruction and its extended
mnemonics (lt, gt, eq) on ppc64le.

Signed-off-by: Matt Brown <matthew.brown....@gmail.com>
---
v2:
        - fixed opcode
        - fixed definition to include the 'if RA=0, a=0' clause
        - fixed ccr bitshifting error
---
 arch/powerpc/lib/sstep.c | 11 +++++++++++
 1 file changed, 11 insertions(+)

diff --git a/arch/powerpc/lib/sstep.c b/arch/powerpc/lib/sstep.c
index 0bcf631..de3d558 100644
--- a/arch/powerpc/lib/sstep.c
+++ b/arch/powerpc/lib/sstep.c
@@ -1239,6 +1239,17 @@ int analyse_instr(struct instruction_op *op, struct 
pt_regs *regs,
 /*
  * Logical instructions
  */
+               case 15:        /* isel */
+                       mb = (instr >> 6) & 0x1f; /* bc */
+                       val = (regs->ccr >> (31 - mb)) & 1;
+                       val2 = (ra) ? regs->gpr[ra] : 0;
+
+                       if (val)
+                               regs->gpr[rd] = val2;
+                       else
+                               regs->gpr[rd] = regs->gpr[rb];
+                       goto logical_done;
+
                case 26:        /* cntlzw */
                        asm("cntlzw %0,%1" : "=r" (regs->gpr[ra]) :
                            "r" (regs->gpr[rd]));
-- 
2.9.3

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