[Qemu-devel] [PATCH 35/35] tcg/arm: Use LDRD to load tlb mask+table

[Richard Henderson]

Signed-off-by: Richard Henderson <address@hidden>
---
 tcg/arm/tcg-target.inc.c | 109 +++++++++++++++++++--------------------
 1 file changed, 52 insertions(+), 57 deletions(-)

diff --git a/tcg/arm/tcg-target.inc.c b/tcg/arm/tcg-target.inc.c
index 4a8c12e9a4..e2fd42e218 100644
--- a/tcg/arm/tcg-target.inc.c
+++ b/tcg/arm/tcg-target.inc.c
@@ -278,6 +278,7 @@ static const char *target_parse_constraint(TCGArgConstraint 
*ct,
         tcg_regset_reset_reg(ct->u.regs, TCG_REG_R0);
         tcg_regset_reset_reg(ct->u.regs, TCG_REG_R1);
         tcg_regset_reset_reg(ct->u.regs, TCG_REG_R2);
+        tcg_regset_reset_reg(ct->u.regs, TCG_REG_R3);
         tcg_regset_reset_reg(ct->u.regs, TCG_REG_R14);
 #endif
         break;
@@ -1253,75 +1254,69 @@ static TCGReg tcg_out_tlb_read(TCGContext *s, TCGReg 
addrlo, TCGReg addrhi,
     unsigned s_bits = opc & MO_SIZE;
     unsigned a_bits = get_alignment_bits(opc);
 
-    /* Load tlb_mask[mmu_idx] and tlb_table[mmu_idx].  */
-    tcg_out_ld(s, TCG_TYPE_I32, TCG_REG_TMP, TCG_AREG0, mask_off);
-    tcg_out_ld(s, TCG_TYPE_I32, TCG_REG_R2, TCG_AREG0, table_off);
-
-    /* Extract the tlb index from the address into TMP.  */
-    tcg_out_dat_reg(s, COND_AL, ARITH_AND, TCG_REG_TMP, TCG_REG_TMP, addrlo,
-                    SHIFT_IMM_LSR(TARGET_PAGE_BITS - CPU_TLB_ENTRY_BITS));
-
     /*
-     * Add the tlb_table pointer, creating the CPUTLBEntry address in R2.
-     * Load the tlb comparator into R0/R1 and the fast path addend into R2.
+     * We don't support inline unaligned acceses, but we can easily
+     * support overalignment checks.
      */
-    if (cmp_off == 0) {
-       if (use_armv6_instructions && TARGET_LONG_BITS == 64) {
-            tcg_out_ldrd_rwb(s, COND_AL, TCG_REG_R0, TCG_REG_R2, TCG_REG_TMP);
-        } else {
-            tcg_out_ld32_rwb(s, COND_AL, TCG_REG_R0, TCG_REG_R2, TCG_REG_TMP);
-        }
-    } else {
-        tcg_out_dat_reg(s, COND_AL, ARITH_ADD,
-                       TCG_REG_R2, TCG_REG_R2, TCG_REG_TMP, 0);
-        if (use_armv6_instructions && TARGET_LONG_BITS == 64) {
-            tcg_out_ldrd_8(s, COND_AL, TCG_REG_R0, TCG_REG_R2, cmp_off);
-        } else {
-            tcg_out_ld32_12(s, COND_AL, TCG_REG_R0, TCG_REG_R2, cmp_off);
-       }
-    }
-    if (!use_armv6_instructions && TARGET_LONG_BITS == 64) {
-        tcg_out_ld32_12(s, COND_AL, TCG_REG_R1, TCG_REG_R2, cmp_off + 4);
-    }
-
-    /* Load the tlb addend.  */
-    tcg_out_ld32_12(s, COND_AL, TCG_REG_R2, TCG_REG_R2,
-                    offsetof(CPUTLBEntry, addend));
-
-    /* Check alignment.  We don't support inline unaligned acceses,
-       but we can easily support overalignment checks.  */
     if (a_bits < s_bits) {
         a_bits = s_bits;
     }
 
-    if (use_armv7_instructions) {
-        tcg_target_ulong mask = ~(TARGET_PAGE_MASK | ((1 << a_bits) - 1));
-        int rot = encode_imm(mask);
-
-        if (rot >= 0) { 
-            tcg_out_dat_imm(s, COND_AL, ARITH_BIC, TCG_REG_TMP, addrlo,
-                            rotl(mask, rot) | (rot << 7));
-        } else {
-            tcg_out_movi32(s, COND_AL, TCG_REG_TMP, mask);
-            tcg_out_dat_reg(s, COND_AL, ARITH_BIC, TCG_REG_TMP,
-                            addrlo, TCG_REG_TMP, 0);
-        }
-        tcg_out_dat_reg(s, COND_AL, ARITH_CMP, 0, TCG_REG_R0, TCG_REG_TMP, 0);
+    /* Load tlb_mask[mmu_idx] and tlb_table[mmu_idx].  */
+    if (use_armv6_instructions) {
+        tcg_out_ldrd_8(s, COND_AL, TCG_REG_R0, TCG_AREG0, fast_off);
     } else {
-        if (a_bits) {
-            tcg_out_dat_imm(s, COND_AL, ARITH_TST, 0, addrlo,
-                            (1 << a_bits) - 1);
-        }
-        tcg_out_dat_reg(s, (a_bits ? COND_EQ : COND_AL), ARITH_CMP,
-                        0, TCG_REG_R0, TCG_REG_TMP,
-                        SHIFT_IMM_LSL(TARGET_PAGE_BITS));
+        tcg_out_ld(s, TCG_TYPE_I32, TCG_REG_R0, TCG_AREG0, mask_off);
+        tcg_out_ld(s, TCG_TYPE_I32, TCG_REG_R1, TCG_AREG0, table_off);
     }
 
+    /* Extract the tlb index from the address into R0.  */
+    tcg_out_dat_reg(s, COND_AL, ARITH_AND, TCG_REG_R0, TCG_REG_R0, addrlo,
+                    SHIFT_IMM_LSR(TARGET_PAGE_BITS - CPU_TLB_ENTRY_BITS));
+
+    /*
+     * Add the tlb_table pointer, creating the CPUTLBEntry address in R1.
+     * Load the tlb comparator into R2/R3 and the fast path addend into R1.
+     */
+    if (cmp_off == 0) {
+        if (use_armv6_instructions && TARGET_LONG_BITS == 64) {
+            tcg_out_ldrd_rwb(s, COND_AL, TCG_REG_R2, TCG_REG_R1, TCG_REG_R0);
+        } else {
+            tcg_out_ld32_rwb(s, COND_AL, TCG_REG_R2, TCG_REG_R1, TCG_REG_R0);
+        }
+    } else {
+        tcg_out_dat_reg(s, COND_AL, ARITH_ADD,
+                       TCG_REG_R1, TCG_REG_R1, TCG_REG_R0, 0);
+        if (use_armv6_instructions && TARGET_LONG_BITS == 64) {
+            tcg_out_ldrd_8(s, COND_AL, TCG_REG_R2, TCG_REG_R1, cmp_off);
+        } else {
+            tcg_out_ld32_12(s, COND_AL, TCG_REG_R2, TCG_REG_R1, cmp_off);
+       }
+    }
+    if (!use_armv6_instructions && TARGET_LONG_BITS == 64) {
+        tcg_out_ld32_12(s, COND_AL, TCG_REG_R3, TCG_REG_R1, cmp_off + 4);
+    }
+
+    /* Shift the non-page bits out.  */
+    tcg_out_dat_reg(s, COND_AL, ARITH_MOV, TCG_REG_R0, 0, addrlo,
+                    SHIFT_IMM_LSR(TARGET_PAGE_BITS));
+
+    /* Load the tlb addend.  */
+    tcg_out_ld32_12(s, COND_AL, TCG_REG_R1, TCG_REG_R1,
+                    offsetof(CPUTLBEntry, addend));
+
+    /* Check alignment, check comparators.  */
+    if (a_bits) {
+        tcg_out_dat_imm(s, COND_AL, ARITH_TST, 0, addrlo, (1 << a_bits) - 1);
+    }
+    tcg_out_dat_reg(s, (a_bits ? COND_EQ : COND_AL), ARITH_CMP, 0,
+                    TCG_REG_R2, TCG_REG_R0, SHIFT_IMM_LSL(TARGET_PAGE_BITS));
+
     if (TARGET_LONG_BITS == 64) {
-        tcg_out_dat_reg(s, COND_EQ, ARITH_CMP, 0, TCG_REG_R1, addrhi, 0);
+        tcg_out_dat_reg(s, COND_EQ, ARITH_CMP, 0, TCG_REG_R3, addrhi, 0);
     }
 
-    return TCG_REG_R2;
+    return TCG_REG_R1;
 }
 
 /* Record the context of a call to the out of line helper code for the slow
-- 
2.17.1