cpu: Move the softmmu tlb to CPUNegativeOffsetState

We have for some time had code within the tcg backends to
handle large positive offsets from env.  This move makes
sure that need not happen.  Indeed, we are able to assert
at build time that simple offsets suffice for all hosts.

Reviewed-by: Alistair Francis <alistair.francis@wdc.com>
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>

1 files changed, 10 insertions, 22 deletions

diff --git a/tcg/sparc/tcg-target.inc.c b/tcg/sparc/tcg-target.inc.c
index 066cb0e892..10b1cea63b 100644
--- a/tcg/sparc/tcg-target.inc.c
+++ b/tcg/sparc/tcg-target.inc.c
@@ -1062,6 +1062,11 @@ static void tcg_out_nop_fill(tcg_insn_unit *p, int count)
 }
 
 #if defined(CONFIG_SOFTMMU)
+
+/* We expect to use a 13-bit negative offset from ENV.  */
+QEMU_BUILD_BUG_ON(TLB_MASK_TABLE_OFS(0) > 0);
+QEMU_BUILD_BUG_ON(TLB_MASK_TABLE_OFS(0) < -(1 << 12));
+
 /* Perform the TLB load and compare.
 
    Inputs:
@@ -1078,9 +1083,9 @@ static void tcg_out_nop_fill(tcg_insn_unit *p, int count)
 static TCGReg tcg_out_tlb_load(TCGContext *s, TCGReg addr, int mem_index,
                                TCGMemOp opc, int which)
 {
-    int mask_off = offsetof(CPUArchState, tlb_.f[mem_index].mask);
-    int table_off = offsetof(CPUArchState, tlb_.f[mem_index].table);
-    TCGReg base = TCG_AREG0;
+    int fast_off = TLB_MASK_TABLE_OFS(mem_index);
+    int mask_off = fast_off + offsetof(CPUTLBDescFast, mask);
+    int table_off = fast_off + offsetof(CPUTLBDescFast, table);
     const TCGReg r0 = TCG_REG_O0;
     const TCGReg r1 = TCG_REG_O1;
     const TCGReg r2 = TCG_REG_O2;
@@ -1088,26 +1093,9 @@ static TCGReg tcg_out_tlb_load(TCGContext *s, TCGReg addr, int mem_index,
     unsigned a_bits = get_alignment_bits(opc);
     tcg_target_long compare_mask;
 
-    if (!check_fit_i32(table_off, 13)) {
-        int table_hi;
-
-        base = r1;
-        if (table_off <= 2 * 0xfff) {
-            table_hi = 0xfff;
-            tcg_out_arithi(s, base, TCG_AREG0, table_hi, ARITH_ADD);
-        } else {
-            table_hi = table_off & ~0x3ff;
-            tcg_out_sethi(s, base, table_hi);
-            tcg_out_arith(s, base, TCG_AREG0, base, ARITH_ADD);
-        }
-        mask_off -= table_hi;
-        table_off -= table_hi;
-        tcg_debug_assert(check_fit_i32(mask_off, 13));
-    }
-
     /* Load tlb_mask[mmu_idx] and tlb_table[mmu_idx].  */
-    tcg_out_ld(s, TCG_TYPE_PTR, r0, base, mask_off);
-    tcg_out_ld(s, TCG_TYPE_PTR, r1, base, table_off);
+    tcg_out_ld(s, TCG_TYPE_PTR, r0, TCG_AREG0, mask_off);
+    tcg_out_ld(s, TCG_TYPE_PTR, r1, TCG_AREG0, table_off);
 
     /* Extract the page index, shifted into place for tlb index.  */
     tcg_out_arithi(s, r2, addr, TARGET_PAGE_BITS - CPU_TLB_ENTRY_BITS,