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authorYang Liu <liuyang22@iscas.ac.cn>2024-12-23 04:41:43 +0800
committerGitHub <noreply@github.com>2024-12-22 21:41:43 +0100
commitfc2a6d4dd19183a68f3d22270a58be683bd62266 (patch)
tree811e7103b04d410426ccc82db54458f0e39d0217 /src
parent85fe4c628e29a18584cdd2e9ca7647196219d0b4 (diff)
downloadbox64-fc2a6d4dd19183a68f3d22270a58be683bd62266.tar.gz
box64-fc2a6d4dd19183a68f3d22270a58be683bd62266.zip
[RV64_DYNAREC] Added a fast path to SHR Ew, Ib (#2188)
Diffstat (limited to 'src')
-rw-r--r--src/dynarec/rv64/dynarec_rv64_66.c20
-rw-r--r--src/dynarec/rv64/rv64_emitter.h6
2 files changed, 19 insertions, 7 deletions
diff --git a/src/dynarec/rv64/dynarec_rv64_66.c b/src/dynarec/rv64/dynarec_rv64_66.c
index 586f46fc..f3fe90c9 100644
--- a/src/dynarec/rv64/dynarec_rv64_66.c
+++ b/src/dynarec/rv64/dynarec_rv64_66.c
@@ -1105,10 +1105,22 @@ uintptr_t dynarec64_66(dynarec_rv64_t* dyn, uintptr_t addr, uintptr_t ip, int ni
                     INST_NAME("SHR Ew, Ib");
                     if (geted_ib(dyn, addr, ninst, nextop) & 0x1f) {
                         SETFLAGS(X_ALL, SF_SET_PENDING, NAT_FLAGS_FUSION); // some flags are left undefined
-                        GETEW(x1, 0);
-                        u8 = (F8) & 0x1f;
-                        emit_shr16c(dyn, ninst, x1, u8, x5, x4, x6);
-                        EWBACK;
+                        if (MODREG && !dyn->insts[ninst].x64.gen_flags) {
+                            // save an srli instruction...
+                            wback = TO_NAT((nextop & 7) + (rex.b << 3));
+                            u8 = (F8) & 0x1f;
+                            SLLI(x1, wback, 48);
+                            SRLI(x1, x1, 48 + u8);
+                            ed = x1;
+                            wb1 = 0;
+                            EWBACK;
+                            if (dyn->insts[ninst].nat_flags_fusion) NAT_FLAGS_OPS(ed, xZR);
+                        } else {
+                            GETEW(x1, 0);
+                            u8 = (F8) & 0x1f;
+                            emit_shr16c(dyn, ninst, x1, u8, x5, x4, x6);
+                            EWBACK;
+                        }
                     } else {
                         FAKEED;
                         F8;
diff --git a/src/dynarec/rv64/rv64_emitter.h b/src/dynarec/rv64/rv64_emitter.h
index 5c3279ea..dbdccf24 100644
--- a/src/dynarec/rv64/rv64_emitter.h
+++ b/src/dynarec/rv64/rv64_emitter.h
@@ -419,11 +419,11 @@
 #define SDz(rs2, rs1, imm12) EMIT(S_type(imm12, rs2, rs1, 0b010 + (1 - rex.is32bits), 0b0100011))
 
 // Shift Left Immediate
-#define SLLI(rd, rs1, imm6) EMIT(I_type(imm6, rs1, 0b001, rd, 0b0010011))
+#define SLLI(rd, rs1, imm6) EMIT(I_type(((imm6) & 0x3f), rs1, 0b001, rd, 0b0010011))
 // Shift Right Logical Immediate
-#define SRLI(rd, rs1, imm6) EMIT(I_type(imm6, rs1, 0b101, rd, 0b0010011))
+#define SRLI(rd, rs1, imm6) EMIT(I_type(((imm6) & 0x3f), rs1, 0b101, rd, 0b0010011))
 // Shift Right Arithmetic Immediate
-#define SRAI(rd, rs1, imm6) EMIT(I_type((imm6) | (0b010000 << 6), rs1, 0b101, rd, 0b0010011))
+#define SRAI(rd, rs1, imm6) EMIT(I_type(((imm6) & 0x3f) | (0b010000 << 6), rs1, 0b101, rd, 0b0010011))
 
 // rd = rs1 + imm12
 #define ADDIW(rd, rs1, imm12) EMIT(I_type((imm12) & 0b111111111111, rs1, 0b000, rd, 0b0011011))