tcg: Drop TCGContext.tlb_dyn_max_bits

This was an extremely minor optimization for aarch64
and x86_64, to use a 32-bit AND instruction when the
guest softmmu tlb maximum was sufficiently small.
Both hosts can simply use a 64-bit AND insn instead.

Signed-off-by: Richard Henderson <richard.henderson@linaro.org>

accel/tcg/translate-all.c

@@ -24,7 +24,6 @@
 #include "tcg/tcg.h"
 #include "exec/mmap-lock.h"
 #include "tb-internal.h"
-#include "tlb-bounds.h"
 #include "exec/tb-flush.h"
 #include "qemu/cacheinfo.h"
 #include "qemu/target-info.h"
@@ -316,7 +315,6 @@ TranslationBlock *tb_gen_code(CPUState *cpu, TCGTBCPUState s)
 #ifdef CONFIG_SOFTMMU
     tcg_ctx->page_bits = TARGET_PAGE_BITS;
     tcg_ctx->page_mask = TARGET_PAGE_MASK;
-    tcg_ctx->tlb_dyn_max_bits = CPU_TLB_DYN_MAX_BITS;
 #endif
     tcg_ctx->guest_mo = cpu->cc->tcg_ops->guest_default_memory_order;
 

include/tcg/tcg.h

@@ -368,7 +368,6 @@ struct TCGContext {
 
     int page_mask;
     uint8_t page_bits;
-    uint8_t tlb_dyn_max_bits;
     TCGBar guest_mo;
 
     TCGRegSet reserved_regs;

tcg/aarch64/tcg-target.c.inc

@@ -1661,7 +1661,6 @@ static TCGLabelQemuLdst *prepare_host_addr(TCGContext *s, HostAddress *h,
         unsigned s_mask = (1u << s_bits) - 1;
         unsigned mem_index = get_mmuidx(oi);
         TCGReg addr_adj;
-        TCGType mask_type;
         uint64_t compare_mask;
 
         ldst = new_ldst_label(s);
@@ -1669,9 +1668,6 @@ static TCGLabelQemuLdst *prepare_host_addr(TCGContext *s, HostAddress *h,
         ldst->oi = oi;
         ldst->addr_reg = addr_reg;
 
-        mask_type = (s->page_bits + s->tlb_dyn_max_bits > 32
-                     ? TCG_TYPE_I64 : TCG_TYPE_I32);
-
         /* Load cpu->neg.tlb.f[mmu_idx].{mask,table} into {tmp0,tmp1}. */
         QEMU_BUILD_BUG_ON(offsetof(CPUTLBDescFast, mask) != 0);
         QEMU_BUILD_BUG_ON(offsetof(CPUTLBDescFast, table) != 8);
@@ -1679,7 +1675,7 @@ static TCGLabelQemuLdst *prepare_host_addr(TCGContext *s, HostAddress *h,
                      tlb_mask_table_ofs(s, mem_index), 1, 0);
 
         /* Extract the TLB index from the address into X0.  */
-        tcg_out_insn(s, 3502S, AND_LSR, mask_type == TCG_TYPE_I64,
+        tcg_out_insn(s, 3502S, AND_LSR, TCG_TYPE_I64,
                      TCG_REG_TMP0, TCG_REG_TMP0, addr_reg,
                      s->page_bits - CPU_TLB_ENTRY_BITS);
 

tcg/i386/tcg-target.c.inc

@@ -2199,10 +2199,8 @@ static TCGLabelQemuLdst *prepare_host_addr(TCGContext *s, HostAddress *h,
             trexw = (ttype == TCG_TYPE_I32 ? 0 : P_REXW);
             if (TCG_TYPE_PTR == TCG_TYPE_I64) {
                 hrexw = P_REXW;
-                if (s->page_bits + s->tlb_dyn_max_bits > 32) {
-                    tlbtype = TCG_TYPE_I64;
-                    tlbrexw = P_REXW;
-                }
+                tlbtype = TCG_TYPE_I64;
+                tlbrexw = P_REXW;
             }
         }