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[RFC,v2,10/24] riscv: tcg-target: Add the relocation functions

Message ID 6e20c8377a588dcb44a1d8ef9efc07499663f59e.1543352682.git.alistair.francis@wdc.com (mailing list archive)
State New, archived
Headers show
Series Add RISC-V TCG backend support | expand

Commit Message

Alistair Francis Nov. 27, 2018, 9:08 p.m. UTC 
Signed-off-by: Alistair Francis <alistair.francis@wdc.com>
Signed-off-by: Michael Clark <mjc@sifive.com>
---
 tcg/riscv/tcg-target.inc.c | 51 ++++++++++++++++++++++++++++++++++++++
 1 file changed, 51 insertions(+)

Comments

Richard Henderson Nov. 28, 2018, 7:38 p.m. UTC | #1 
On 11/27/18 1:08 PM, Alistair Francis wrote:
> Signed-off-by: Alistair Francis <alistair.francis@wdc.com>
> Signed-off-by: Michael Clark <mjc@sifive.com>
> ---
>  tcg/riscv/tcg-target.inc.c | 51 ++++++++++++++++++++++++++++++++++++++
>  1 file changed, 51 insertions(+)

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


r~
diff mbox series

Patch

diff --git a/tcg/riscv/tcg-target.inc.c b/tcg/riscv/tcg-target.inc.c
index ca7ae8939a..9c48679f11 100644
--- a/tcg/riscv/tcg-target.inc.c
+++ b/tcg/riscv/tcg-target.inc.c
@@ -383,6 +383,57 @@  static void tcg_out_opc_jump(TCGContext *s, RISCVInsn opc,
     tcg_out32(s, encode_uj(opc, rd, imm));
 }
 
+/*
+ * Relocations
+ */
+
+static void reloc_sbimm12(tcg_insn_unit *code_ptr, tcg_insn_unit *target)
+{
+    intptr_t offset = (intptr_t)target - (intptr_t)code_ptr;
+    tcg_debug_assert(offset == sextract32(offset, 1, 12) << 1);
+
+    code_ptr[0] |= encode_sbimm12(offset);
+}
+
+static void reloc_jimm20(tcg_insn_unit *code_ptr, tcg_insn_unit *target)
+{
+    intptr_t offset = (intptr_t)target - (intptr_t)code_ptr;
+    tcg_debug_assert(offset == sextract32(offset, 1, 20) << 1);
+
+    code_ptr[0] |= encode_ujimm12(offset);
+}
+
+static void reloc_call(tcg_insn_unit *code_ptr, tcg_insn_unit *target)
+{
+    intptr_t offset = (intptr_t)target - (intptr_t)code_ptr;
+    tcg_debug_assert(offset == (int32_t)offset);
+
+    int32_t hi20 = ((offset + 0x800) >> 12) << 12;
+    int32_t lo12 = offset - hi20;
+
+    code_ptr[0] |= encode_uimm20(hi20);
+    code_ptr[1] |= encode_imm12(lo12);
+}
+
+static void patch_reloc(tcg_insn_unit *code_ptr, int type,
+                        intptr_t value, intptr_t addend)
+{
+    tcg_debug_assert(addend == 0);
+    switch (type) {
+    case R_RISCV_BRANCH:
+        reloc_sbimm12(code_ptr, (tcg_insn_unit *)value);
+        break;
+    case R_RISCV_JAL:
+        reloc_jimm20(code_ptr, (tcg_insn_unit *)value);
+        break;
+    case R_RISCV_CALL:
+        reloc_call(code_ptr, (tcg_insn_unit *)value);
+        break;
+    default:
+        tcg_abort();
+    }
+}
+
 void tb_target_set_jmp_target(uintptr_t tc_ptr, uintptr_t jmp_addr,
                               uintptr_t addr)
 {