[PATCH v2 01/50] accel/tcg: Add bitreverse and funnel-shift runtime helper functions

Adds necessary helper functions for mapping LLVM IR onto TCG.
Specifically, helpers corresponding to the bitreverse and funnel-shift
intrinsics in LLVM.

Note: these may be converted to more efficient implementations in the
future, but for the time being it allows helper-to-tcg to support a
wider subset of LLVM IR.

Signed-off-by: Anton Johansson <[email protected]>
--
TODO: `tcg_gen_*()` variants will be added in the next version, it
slipped through (Richard).
---
 accel/tcg/tcg-runtime.c | 28 ++++++++++++++++++++++++++++
 accel/tcg/tcg-runtime.h |  6 ++++++
 2 files changed, 34 insertions(+)

diff --git a/accel/tcg/tcg-runtime.c b/accel/tcg/tcg-runtime.c
index 7c0aab98a8..d42c00736b 100644
--- a/accel/tcg/tcg-runtime.c
+++ b/accel/tcg/tcg-runtime.c
@@ -24,6 +24,7 @@
 #include "qemu/osdep.h"
 #include "qemu/host-utils.h"
 #include "exec/cpu-common.h"
+#include "qemu/int128.h"
 #include "exec/helper-proto-common.h"
 #include "accel/tcg/cpu-loop.h"
 #include "accel/tcg/getpc.h"
@@ -54,8 +55,30 @@ uint32_t HELPER(remu_i32)(uint32_t arg1, uint32_t arg2)
     return arg1 % arg2;
 }
 
+uint32_t HELPER(bitreverse8_i32)(uint32_t x)
+{
+  return revbit8((uint8_t) x);
+}
+
+uint32_t HELPER(bitreverse16_i32)(uint32_t x)
+{
+  return revbit16((uint16_t) x);
+}
+
+uint32_t HELPER(bitreverse32_i32)(uint32_t x)
+{
+  return revbit32(x);
+}
+
 /* 64-bit helpers */
 
+uint64_t HELPER(fshl_i64)(uint64_t a, uint64_t b, uint64_t c)
+{
+    Int128 d = int128_make128(b, a);
+    Int128 shift = int128_lshift(d, c);
+    return int128_gethi(shift);
+}
+
 int64_t HELPER(div_i64)(int64_t arg1, int64_t arg2)
 {
     return arg1 / arg2;
@@ -76,6 +99,11 @@ uint64_t HELPER(remu_i64)(uint64_t arg1, uint64_t arg2)
     return arg1 % arg2;
 }
 
+uint64_t HELPER(bitreverse64_i64)(uint64_t x)
+{
+    return revbit64(x);
+}
+
 uint64_t HELPER(muluh_i64)(uint64_t arg1, uint64_t arg2)
 {
     uint64_t l, h;
diff --git a/accel/tcg/tcg-runtime.h b/accel/tcg/tcg-runtime.h
index 0b832176b3..197d658b40 100644
--- a/accel/tcg/tcg-runtime.h
+++ b/accel/tcg/tcg-runtime.h
@@ -2,11 +2,17 @@ DEF_HELPER_FLAGS_2(div_i32, TCG_CALL_NO_RWG_SE, s32, s32, s32)
 DEF_HELPER_FLAGS_2(rem_i32, TCG_CALL_NO_RWG_SE, s32, s32, s32)
 DEF_HELPER_FLAGS_2(divu_i32, TCG_CALL_NO_RWG_SE, i32, i32, i32)
 DEF_HELPER_FLAGS_2(remu_i32, TCG_CALL_NO_RWG_SE, i32, i32, i32)
+DEF_HELPER_FLAGS_1(bitreverse8_i32,  TCG_CALL_NO_RWG_SE, i32, i32)
+DEF_HELPER_FLAGS_1(bitreverse16_i32, TCG_CALL_NO_RWG_SE, i32, i32)
+DEF_HELPER_FLAGS_1(bitreverse32_i32, TCG_CALL_NO_RWG_SE, i32, i32)
 
 DEF_HELPER_FLAGS_2(div_i64, TCG_CALL_NO_RWG_SE, s64, s64, s64)
 DEF_HELPER_FLAGS_2(rem_i64, TCG_CALL_NO_RWG_SE, s64, s64, s64)
 DEF_HELPER_FLAGS_2(divu_i64, TCG_CALL_NO_RWG_SE, i64, i64, i64)
 DEF_HELPER_FLAGS_2(remu_i64, TCG_CALL_NO_RWG_SE, i64, i64, i64)
+DEF_HELPER_FLAGS_1(bitreverse64_i64, TCG_CALL_NO_RWG_SE, i64, i64)
+
+DEF_HELPER_FLAGS_3(fshl_i64, TCG_CALL_NO_RWG_SE, i64, i64, i64, i64)
 
 DEF_HELPER_FLAGS_2(mulsh_i64, TCG_CALL_NO_RWG_SE, s64, s64, s64)
 DEF_HELPER_FLAGS_2(muluh_i64, TCG_CALL_NO_RWG_SE, i64, i64, i64)
-- 
2.52.0