@@ -323,6 +323,10 @@ typedef enum {
/* Conditional select instructions */
INSN_CSEL = 0x1a800000,
INSN_CSINC = 0x1a800400,
+
+ /* PC relative addressing instructions */
+ INSN_ADR = 0x10000000,
+ INSN_ADRP = 0x90000000,
} AArch64Insn;
static inline enum aarch64_ldst_op_data
@@ -510,6 +514,12 @@ static inline void tcg_fmt_Rd_uimm(TCGContext *s, AArch64Insn insn,
tcg_out32(s, insn | sf << 31 | shift << (21 - 4) | half << 5 | rd);
}
+static inline void tcg_fmt_Rd_disp21(TCGContext *s, AArch64Insn insn,
+ TCGReg rd, tcg_target_long disp)
+{
+ tcg_out32(s, insn | (disp & 3) << 29 | (disp & 0x1ffffc) << (5 - 2) | rd);
+}
+
static inline void tcg_out_ldst_9(TCGContext *s,
enum aarch64_ldst_op_data op_data,
enum aarch64_ldst_op_type op_type,
@@ -561,7 +571,7 @@ static void tcg_out_movi(TCGContext *s, TCGType type, TCGReg rd,
AArch64Insn insn;
int i, wantinv, shift;
tcg_target_long svalue = value;
- tcg_target_long ivalue, imask;
+ tcg_target_long ivalue, imask, disp;
/* For 32-bit values, discard potential garbage in value. For 64-bit
values within [2**31, 2**32-1], we can create smaller sequences by
@@ -593,6 +603,17 @@ static void tcg_out_movi(TCGContext *s, TCGType type, TCGReg rd,
return;
}
+ /* Look for host pointer values within 4G of the PC. This happens
+ often when loading pointers to QEMU's own data structures. */
+ disp = (value >> 12) - ((intptr_t)s->code_ptr >> 12);
+ if (disp == sextract64(disp, 0, 21)) {
+ tcg_fmt_Rd_disp21(s, INSN_ADRP, rd, disp);
+ if (value & 0xfff) {
+ tcg_fmt_Rdn_aimm(s, INSN_ADDI, type, rd, rd, value & 0xfff);
+ }
+ return;
+ }
+
/* Would it take fewer insns to begin with MOVN? For the value and its
inverse, count the number of 16-bit lanes that are 0. For the benefit
of 32-bit quantities, compare the zero-extended normal value vs the
Loading an qemu pointer as an immediate happens often. E.g. - exit_tb $0x7fa8140013 + exit_tb $0x7f81ee0013 ... - : d2800260 mov x0, #0x13 - : f2b50280 movk x0, #0xa814, lsl #16 - : f2c00fe0 movk x0, #0x7f, lsl #32 + : 90ff1000 adrp x0, 0x7f81ee0000 + : 91004c00 add x0, x0, #0x13 Signed-off-by: Richard Henderson <rth@twiddle.net> --- tcg/aarch64/tcg-target.c | 23 ++++++++++++++++++++++- 1 file changed, 22 insertions(+), 1 deletion(-)