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[Qemu-devel] [PULL 14/42] tcg/riscv: Add the add2 and sub2 instructions
From: |
Richard Henderson |
Subject: |
[Qemu-devel] [PULL 14/42] tcg/riscv: Add the add2 and sub2 instructions |
Date: |
Wed, 26 Dec 2018 07:55:01 +1100 |
From: Alistair Francis <address@hidden>
Signed-off-by: Alistair Francis <address@hidden>
Reviewed-by: Richard Henderson <address@hidden>
Message-Id: <address@hidden>
Signed-off-by: Richard Henderson <address@hidden>
---
tcg/riscv/tcg-target.inc.c | 55 ++++++++++++++++++++++++++++++++++++++
1 file changed, 55 insertions(+)
diff --git a/tcg/riscv/tcg-target.inc.c b/tcg/riscv/tcg-target.inc.c
index 65718df7ad..5da850b957 100644
--- a/tcg/riscv/tcg-target.inc.c
+++ b/tcg/riscv/tcg-target.inc.c
@@ -695,3 +695,58 @@ static bool tcg_out_sti(TCGContext *s, TCGType type,
TCGArg val,
}
return false;
}
+
+static void tcg_out_addsub2(TCGContext *s,
+ TCGReg rl, TCGReg rh,
+ TCGReg al, TCGReg ah,
+ TCGArg bl, TCGArg bh,
+ bool cbl, bool cbh, bool is_sub, bool is32bit)
+{
+ const RISCVInsn opc_add = is32bit ? OPC_ADDW : OPC_ADD;
+ const RISCVInsn opc_addi = is32bit ? OPC_ADDIW : OPC_ADDI;
+ const RISCVInsn opc_sub = is32bit ? OPC_SUBW : OPC_SUB;
+ TCGReg th = TCG_REG_TMP1;
+
+ /* If we have a negative constant such that negating it would
+ make the high part zero, we can (usually) eliminate one insn. */
+ if (cbl && cbh && bh == -1 && bl != 0) {
+ bl = -bl;
+ bh = 0;
+ is_sub = !is_sub;
+ }
+
+ /* By operating on the high part first, we get to use the final
+ carry operation to move back from the temporary. */
+ if (!cbh) {
+ tcg_out_opc_reg(s, (is_sub ? opc_sub : opc_add), th, ah, bh);
+ } else if (bh != 0 || ah == rl) {
+ tcg_out_opc_imm(s, opc_addi, th, ah, (is_sub ? -bh : bh));
+ } else {
+ th = ah;
+ }
+
+ /* Note that tcg optimization should eliminate the bl == 0 case. */
+ if (is_sub) {
+ if (cbl) {
+ tcg_out_opc_imm(s, OPC_SLTIU, TCG_REG_TMP0, al, bl);
+ tcg_out_opc_imm(s, opc_addi, rl, al, -bl);
+ } else {
+ tcg_out_opc_reg(s, OPC_SLTU, TCG_REG_TMP0, al, bl);
+ tcg_out_opc_reg(s, opc_sub, rl, al, bl);
+ }
+ tcg_out_opc_reg(s, opc_sub, rh, th, TCG_REG_TMP0);
+ } else {
+ if (cbl) {
+ tcg_out_opc_imm(s, opc_addi, rl, al, bl);
+ tcg_out_opc_imm(s, OPC_SLTIU, TCG_REG_TMP0, rl, bl);
+ } else if (rl == al && rl == bl) {
+ tcg_out_opc_imm(s, OPC_SLTI, TCG_REG_TMP0, al, 0);
+ tcg_out_opc_reg(s, opc_addi, rl, al, bl);
+ } else {
+ tcg_out_opc_reg(s, opc_add, rl, al, bl);
+ tcg_out_opc_reg(s, OPC_SLTU, TCG_REG_TMP0,
+ rl, (rl == bl ? al : bl));
+ }
+ tcg_out_opc_reg(s, opc_add, rh, th, TCG_REG_TMP0);
+ }
+}
--
2.17.2
- [Qemu-devel] [PULL 03/42] linux-user: Add host dependency for RISC-V 64-bit, (continued)
- [Qemu-devel] [PULL 03/42] linux-user: Add host dependency for RISC-V 64-bit, Richard Henderson, 2018/12/25
- [Qemu-devel] [PULL 04/42] exec: Add RISC-V GCC poison macro, Richard Henderson, 2018/12/25
- [Qemu-devel] [PULL 05/42] tcg/riscv: Add the tcg-target.h file, Richard Henderson, 2018/12/25
- [Qemu-devel] [PULL 06/42] tcg/riscv: Add the tcg target registers, Richard Henderson, 2018/12/25
- [Qemu-devel] [PULL 07/42] tcg/riscv: Add support for the constraints, Richard Henderson, 2018/12/25
- [Qemu-devel] [PULL 08/42] tcg/riscv: Add the immediate encoders, Richard Henderson, 2018/12/25
- [Qemu-devel] [PULL 09/42] tcg/riscv: Add the instruction emitters, Richard Henderson, 2018/12/25
- [Qemu-devel] [PULL 10/42] tcg/riscv: Add the relocation functions, Richard Henderson, 2018/12/25
- [Qemu-devel] [PULL 11/42] tcg/riscv: Add the mov and movi instruction, Richard Henderson, 2018/12/25
- [Qemu-devel] [PULL 12/42] tcg/riscv: Add the extract instructions, Richard Henderson, 2018/12/25
- [Qemu-devel] [PULL 14/42] tcg/riscv: Add the add2 and sub2 instructions,
Richard Henderson <=
- [Qemu-devel] [PULL 13/42] tcg/riscv: Add the out load and store instructions, Richard Henderson, 2018/12/25
- [Qemu-devel] [PULL 15/42] tcg/riscv: Add branch and jump instructions, Richard Henderson, 2018/12/25
- [Qemu-devel] [PULL 16/42] tcg/riscv: Add slowpath load and store instructions, Richard Henderson, 2018/12/25
- [Qemu-devel] [PULL 17/42] tcg/riscv: Add direct load and store instructions, Richard Henderson, 2018/12/25
- [Qemu-devel] [PULL 18/42] tcg/riscv: Add the out op decoder, Richard Henderson, 2018/12/25
- [Qemu-devel] [PULL 19/42] tcg/riscv: Add the prologue generation and register the JIT, Richard Henderson, 2018/12/25
- [Qemu-devel] [PULL 20/42] tcg/riscv: Add the target init code, Richard Henderson, 2018/12/25
- [Qemu-devel] [PULL 21/42] tcg: Add RISC-V cpu signal handler, Richard Henderson, 2018/12/25
- [Qemu-devel] [PULL 22/42] disas: Add RISC-V support, Richard Henderson, 2018/12/25
- [Qemu-devel] [PULL 23/42] configure: Add support for building RISC-V host, Richard Henderson, 2018/12/25