pike.git/ src/ code/ amd64.c

2018-10-16

2018-10-16 20:25:40 by Tobias S. Josefowitz <tobij@tobij.de>

• 45009af643dbece75d3ee615046b25e76a5438e8 (5 lines) (+5/-0) ^{[ Show | Annotate ]}
  Branch: 8.0

Compiler [amd64]: Keep stack alignment before calling C code

GCC 8 started to emit movaps instructions with (%RSP) as destination,
leading to GPF in case it was not properly aligned.

2394:    LABEL_C;/* all done, res in RAX */    /* free value, store result */    push( P_REG_RAX ); +  sub_reg_imm(P_REG_RSP, 8); /* Align on 16 bytes. */    amd64_free_svalue( P_REG_RBX, 0 ); -  +  add_reg_imm(P_REG_RSP, 8);    pop( P_REG_RAX );    mov_reg_mem(P_REG_RAX, P_REG_RBX, OFFSETOF(svalue, u.integer));    mov_imm_mem(PIKE_T_INT, P_REG_RBX, OFFSETOF(svalue, tu.t.type));
2806:    /* SVALUE_PTR optimization */    mov_mem_reg( sp_reg, -3*sizeof(struct svalue)+8, P_REG_RDX );    push( P_REG_RDX ); +  sub_reg_imm(P_REG_RSP, 8); /* Align on 16 bytes. */    /* Free old value. */    amd64_free_svalue( P_REG_RDX, 0 ); -  +  add_reg_imm(P_REG_RSP, 8);    pop( P_REG_RDX );       /* Assign new value. */