riscv/rocket-chip
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Don't take interrupts on instructions in branch shadow

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In situations like

       j 1f
       nop
    1: nop

the interrupt could be taken on the first nop.
This commit is contained in:
Andrew Waterman 2016-06-28 12:47:49 -07:00
parent a70dee17ea
commit c10691b616
1 changed files with 3 additions and 2 deletions
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5
rocket/src/main/scala/rocket.scala
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@ -327,6 +327,7 @@ class Rocket(implicit p: Parameters) extends CoreModule()(p) {
}
// replay inst in ex stage?
val ex_pc_valid = ex_reg_valid || ex_reg_xcpt_interrupt
val wb_dcache_miss = wb_ctrl.mem && !io.dmem.resp.valid
val replay_ex_structural = ex_ctrl.mem && !io.dmem.req.ready ||
ex_ctrl.div && !div.io.req.ready
@ -347,7 +348,7 @@ class Rocket(implicit p: Parameters) extends CoreModule()(p) {
Mux(mem_ctrl.jal, ImmGen(IMM_UJ, mem_reg_inst), SInt(4)))
val mem_int_wdata = Mux(mem_ctrl.jalr, mem_br_target, mem_reg_wdata.toSInt).toUInt
val mem_npc = (Mux(mem_ctrl.jalr, encodeVirtualAddress(mem_reg_wdata, mem_reg_wdata).toSInt, mem_br_target) & SInt(-2)).toUInt
val mem_wrong_npc = Mux(ex_reg_valid, mem_npc =/= ex_reg_pc, Mux(io.imem.resp.valid, mem_npc =/= id_pc, Bool(true)))
val mem_wrong_npc = Mux(ex_pc_valid, mem_npc =/= ex_reg_pc, Mux(io.imem.resp.valid, mem_npc =/= id_pc, Bool(true)))
val mem_npc_misaligned = mem_npc(1)
val mem_cfi = mem_ctrl.branch || mem_ctrl.jalr || mem_ctrl.jal
val mem_cfi_taken = (mem_ctrl.branch && mem_br_taken) || mem_ctrl.jalr || mem_ctrl.jal
@ -363,7 +364,7 @@ class Rocket(implicit p: Parameters) extends CoreModule()(p) {
mem_reg_xcpt_interrupt := !take_pc_mem_wb && ex_reg_xcpt_interrupt
when (ex_xcpt) { mem_reg_cause := ex_cause }
when (ex_reg_valid || ex_reg_xcpt_interrupt) {
when (ex_pc_valid) {
mem_ctrl := ex_ctrl
mem_reg_load := ex_ctrl.mem && isRead(ex_ctrl.mem_cmd)
mem_reg_store := ex_ctrl.mem && isWrite(ex_ctrl.mem_cmd)