Hexagon (target/hexagon) Remove PC from the runtime state

Add pc field to Packet structure
For helpers that need PC, pass an extra argument
Remove slot arg from conditional jump helpers
On a trap0, copy pkt->pc into hex_gpr[HEX_REG_PC]

Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Signed-off-by: Taylor Simpson <tsimpson@quicinc.com>
Message-Id: <20221108162906.3166-6-tsimpson@quicinc.com>

target/hexagon/gen_helper_funcs.py

@@ -241,6 +241,10 @@ def gen_helper_function(f, tag, tagregs, tagimms):
         if (hex_common.need_pkt_has_multi_cof(tag)):
             f.write(", uint32_t pkt_has_multi_cof")
 
+        if hex_common.need_PC(tag):
+            if i > 0: f.write(", ")
+            f.write("target_ulong PC")
+            i += 1
         if hex_common.need_slot(tag):
             if i > 0: f.write(", ")
             f.write("uint32_t slot")

target/hexagon/gen_helper_protos.py

@@ -85,6 +85,7 @@ def gen_helper_prototype(f, tag, tagregs, tagimms):
             if hex_common.need_pkt_has_multi_cof(tag): def_helper_size += 1
             if hex_common.need_part1(tag): def_helper_size += 1
             if hex_common.need_slot(tag): def_helper_size += 1
+            if hex_common.need_PC(tag): def_helper_size += 1
             f.write('DEF_HELPER_%s(%s' % (def_helper_size, tag))
             ## The return type is void
             f.write(', void' )
@@ -93,6 +94,7 @@ def gen_helper_prototype(f, tag, tagregs, tagimms):
             if hex_common.need_pkt_has_multi_cof(tag): def_helper_size += 1
             if hex_common.need_part1(tag): def_helper_size += 1
             if hex_common.need_slot(tag): def_helper_size += 1
+            if hex_common.need_PC(tag): def_helper_size += 1
             f.write('DEF_HELPER_%s(%s' % (def_helper_size, tag))
 
         ## Generate the qemu DEF_HELPER type for each result
@@ -131,6 +133,7 @@ def gen_helper_prototype(f, tag, tagregs, tagimms):
         ## Add the arguments for the instruction pkt_has_multi_cof, slot and
         ## part1 (if needed)
         if hex_common.need_pkt_has_multi_cof(tag): f.write(', i32')
+        if hex_common.need_PC(tag): f.write(', i32')
         if hex_common.need_slot(tag): f.write(', i32' )
         if hex_common.need_part1(tag): f.write(' , i32' )
         f.write(')\n')

target/hexagon/gen_tcg.h

@@ -750,4 +750,11 @@
         RsV = RsV; \
     } while (0)
 
+#define fGEN_TCG_J2_trap0(SHORTCODE) \
+    do { \
+        uiV = uiV; \
+        tcg_gen_movi_tl(hex_gpr[HEX_REG_PC], ctx->pkt->pc); \
+        TCGv excp = tcg_constant_tl(HEX_EXCP_TRAP0); \
+        gen_helper_raise_exception(cpu_env, excp); \
+    } while (0)
 #endif

target/hexagon/gen_tcg_funcs.py

@@ -629,6 +629,8 @@ def gen_tcg_func(f, tag, regs, imms):
             f.write("    TCGv part1 = tcg_constant_tl(insn->part1);\n")
         if hex_common.need_slot(tag):
             f.write("    TCGv slot = tcg_constant_tl(insn->slot);\n")
+        if hex_common.need_PC(tag):
+            f.write("    TCGv PC = tcg_constant_tl(ctx->pkt->pc);\n")
         f.write("    gen_helper_%s(" % (tag))
         i=0
         ## If there is a scalar result, it is the return type
@@ -659,6 +661,7 @@ def gen_tcg_func(f, tag, regs, imms):
 
         if hex_common.need_pkt_has_multi_cof(tag):
             f.write(", pkt_has_multi_cof")
+        if hex_common.need_PC(tag): f.write(", PC")
         if hex_common.need_slot(tag): f.write(", slot")
         if hex_common.need_part1(tag): f.write(", part1" )
         f.write(");\n")

target/hexagon/hex_common.py

@@ -194,7 +194,8 @@ def is_new_val(regtype, regid, tag):
     return regtype+regid+'N' in semdict[tag]
 
 def need_slot(tag):
-    if ('A_CONDEXEC' in attribdict[tag] or
+    if (('A_CONDEXEC' in attribdict[tag] and
+         'A_JUMP' not in attribdict[tag]) or
         'A_STORE' in attribdict[tag] or
         'A_LOAD' in attribdict[tag]):
         return 1
@@ -207,6 +208,9 @@ def need_part1(tag):
 def need_ea(tag):
     return re.compile(r"\bEA\b").search(semdict[tag])
 
+def need_PC(tag):
+    return 'A_IMPLICIT_READS_PC' in attribdict[tag]
+
 def need_pkt_has_multi_cof(tag):
     return 'A_COF' in attribdict[tag]
 

target/hexagon/insn.h

@@ -54,6 +54,7 @@ typedef struct Instruction Insn;
 struct Packet {
     uint16_t num_insns;
     uint16_t encod_pkt_size_in_bytes;
+    uint32_t pc;
 
     /* Pre-decodes about COF */
     bool pkt_has_cof;          /* Has any change-of-flow */

target/hexagon/macros.h

@@ -398,7 +398,7 @@ static inline TCGv gen_read_ireg(TCGv result, TCGv val, int shift)
 #else
 #define fREAD_GP() READ_REG(HEX_REG_GP)
 #endif
-#define fREAD_PC() (READ_REG(HEX_REG_PC))
+#define fREAD_PC() (PC)
 
 #define fREAD_NPC() (env->next_PC & (0xfffffffe))
 

target/hexagon/translate.c

@@ -194,11 +194,6 @@ static bool check_for_attrib(Packet *pkt, int attrib)
     return false;
 }
 
-static bool need_pc(Packet *pkt)
-{
-    return check_for_attrib(pkt, A_IMPLICIT_READS_PC);
-}
-
 static bool need_slot_cancelled(Packet *pkt)
 {
     return check_for_attrib(pkt, A_CONDEXEC);
@@ -241,9 +236,6 @@ static void gen_start_packet(DisasContext *ctx)
     }
 
     /* Initialize the runtime state for packet semantics */
-    if (need_pc(pkt)) {
-        tcg_gen_movi_tl(hex_gpr[HEX_REG_PC], ctx->base.pc_next);
-    }
     if (need_slot_cancelled(pkt)) {
         tcg_gen_movi_tl(hex_slot_cancelled, 0);
     }
@@ -772,6 +764,7 @@ static void decode_and_translate_packet(CPUHexagonState *env, DisasContext *ctx)
     }
 
     if (decode_packet(nwords, words, &pkt, false) > 0) {
+        pkt.pc = ctx->base.pc_next;
         HEX_DEBUG_PRINT_PKT(&pkt);
         ctx->pkt = &pkt;
         gen_start_packet(ctx);