[Qemu-devel] [PATCH v2 6/7] tcg: Introduce zero and sign-extended versions of load helpers

[Richard Henderson <rth@twiddle.net>]

Signed-off-by: Richard Henderson <rth@twiddle.net>
---
 include/exec/softmmu_template.h | 58 ++++++++++++++++++++++++++++++++---------
 tcg/i386/tcg-target.c           |  6 ++---
 tcg/tcg.h                       | 21 ++++++++++-----
 3 files changed, 64 insertions(+), 21 deletions(-)

diff --git a/include/exec/softmmu_template.h b/include/exec/softmmu_template.h
index f9922e2..5bbc56a 100644
--- a/include/exec/softmmu_template.h
+++ b/include/exec/softmmu_template.h
@@ -29,23 +29,39 @@
 #if DATA_SIZE == 8
 #define SUFFIX q
 #define LSUFFIX q
-#define DATA_TYPE uint64_t
+#define SDATA_TYPE  int64_t
 #elif DATA_SIZE == 4
 #define SUFFIX l
 #define LSUFFIX l
-#define DATA_TYPE uint32_t
+#define SDATA_TYPE  int32_t
 #elif DATA_SIZE == 2
 #define SUFFIX w
 #define LSUFFIX uw
-#define DATA_TYPE uint16_t
+#define SDATA_TYPE  int16_t
 #elif DATA_SIZE == 1
 #define SUFFIX b
 #define LSUFFIX ub
-#define DATA_TYPE uint8_t
+#define SDATA_TYPE  int8_t
 #else
 #error unsupported data size
 #endif
 
+#define DATA_TYPE   glue(u, SDATA_TYPE)
+
+/* For the benefit of TCG generated code, we want to avoid the complication
+   of ABI-specific return type promotion and always return a value extended
+   to the register size of the host.  This is tcg_target_long, except in the
+   case of a 32-bit host and 64-bit data, and for that we always have
+   uint64_t.  Don't bother with this widened value for SOFTMMU_CODE_ACCESS.  */
+#if defined(SOFTMMU_CODE_ACCESS) || DATA_SIZE == 8
+# define WORD_TYPE  DATA_TYPE
+# define USUFFIX    SUFFIX
+#else
+# define WORD_TYPE  tcg_target_ulong
+# define USUFFIX    glue(u, SUFFIX)
+# define SSUFFIX    glue(s, SUFFIX)
+#endif
+
 #ifdef SOFTMMU_CODE_ACCESS
 #define READ_ACCESS_TYPE 2
 #define ADDR_READ addr_code
@@ -77,10 +93,10 @@ static inline DATA_TYPE glue(io_read, SUFFIX)(CPUArchState *env,
 #ifdef SOFTMMU_CODE_ACCESS
 static
 #endif
-DATA_TYPE
-glue(glue(helper_ret_ld, SUFFIX), MMUSUFFIX)(CPUArchState *env,
-                                             target_ulong addr, int mmu_idx,
-                                             uintptr_t retaddr)
+WORD_TYPE
+glue(glue(helper_ret_ld, USUFFIX), MMUSUFFIX)(CPUArchState *env,
+                                              target_ulong addr, int mmu_idx,
+                                              uintptr_t retaddr)
 {
     int index = (addr >> TARGET_PAGE_BITS) & (CPU_TLB_SIZE - 1);
     target_ulong tlb_addr = env->tlb_table[mmu_idx][index].ADDR_READ;
@@ -126,9 +142,9 @@ glue(glue(helper_ret_ld, SUFFIX), MMUSUFFIX)(CPUArchState *env,
         addr2 = addr1 + DATA_SIZE;
         /* Note the adjustment at the beginning of the function.
            Undo that for the recursion.  */
-        res1 = glue(glue(helper_ret_ld, SUFFIX), MMUSUFFIX)
+        res1 = glue(glue(helper_ret_ld, USUFFIX), MMUSUFFIX)
             (env, addr1, mmu_idx, retaddr + GETPC_ADJ);
-        res2 = glue(glue(helper_ret_ld, SUFFIX), MMUSUFFIX)
+        res2 = glue(glue(helper_ret_ld, USUFFIX), MMUSUFFIX)
             (env, addr2, mmu_idx, retaddr + GETPC_ADJ);
         shift = (addr & (DATA_SIZE - 1)) * 8;
 #ifdef TARGET_WORDS_BIGENDIAN
@@ -147,19 +163,33 @@ glue(glue(helper_ret_ld, SUFFIX), MMUSUFFIX)(CPUArchState *env,
 #endif
 
     haddr = addr + env->tlb_table[mmu_idx][index].addend;
-    return glue(glue(ld, LSUFFIX), _raw)((uint8_t *)haddr);
+    /* Note that ldl_raw is defined with type "int".  */
+    return (DATA_TYPE) glue(glue(ld, LSUFFIX), _raw)((uint8_t *)haddr);
 }
 
 DATA_TYPE
 glue(glue(helper_ld, SUFFIX), MMUSUFFIX)(CPUArchState *env, target_ulong addr,
                                          int mmu_idx)
 {
-    return glue(glue(helper_ret_ld, SUFFIX), MMUSUFFIX)(env, addr, mmu_idx,
+    return glue(glue(helper_ret_ld, USUFFIX), MMUSUFFIX)(env, addr, mmu_idx,
                                                         GETRA_EXT());
 }
 
 #ifndef SOFTMMU_CODE_ACCESS
 
+/* Provide signed versions of the load routines as well.  We can of course
+   avoid this for 64-bit data, or for 32-bit data on 32-bit host.  */
+#if DATA_SIZE * 8 < TCG_TARGET_REG_BITS
+WORD_TYPE
+glue(glue(helper_ret_ld, SSUFFIX), MMUSUFFIX)(CPUArchState *env,
+                                              target_ulong addr, int mmu_idx,
+                                              uintptr_t retaddr)
+{
+    return (SDATA_TYPE) glue(glue(helper_ret_ld, USUFFIX), MMUSUFFIX)
+        (env, addr, mmu_idx, retaddr);
+}
+#endif
+
 static inline void glue(io_write, SUFFIX)(CPUArchState *env,
                                           hwaddr physaddr,
                                           DATA_TYPE val,
@@ -267,3 +297,7 @@ glue(glue(helper_st, SUFFIX), MMUSUFFIX)(CPUArchState *env, target_ulong addr,
 #undef LSUFFIX
 #undef DATA_SIZE
 #undef ADDR_READ
+#undef WORD_TYPE
+#undef SDATA_TYPE
+#undef USUFFIX
+#undef SSUFFIX
diff --git a/tcg/i386/tcg-target.c b/tcg/i386/tcg-target.c
index 4c98cc4..5aee0fa 100644
--- a/tcg/i386/tcg-target.c
+++ b/tcg/i386/tcg-target.c
@@ -1026,9 +1026,9 @@ static void tcg_out_jmp(TCGContext *s, tcg_target_long dest)
  *                                     int mmu_idx, uintptr_t ra)
  */
 static const void * const qemu_ld_helpers[4] = {
-    helper_ret_ldb_mmu,
-    helper_ret_ldw_mmu,
-    helper_ret_ldl_mmu,
+    helper_ret_ldub_mmu,
+    helper_ret_lduw_mmu,
+    helper_ret_ldul_mmu,
     helper_ret_ldq_mmu,
 };
 
diff --git a/tcg/tcg.h b/tcg/tcg.h
index eeff6b7..27f6ee5 100644
--- a/tcg/tcg.h
+++ b/tcg/tcg.h
@@ -750,15 +750,24 @@ void tcg_out_tb_finalize(TCGContext *s);
  * Memory helpers that will be used by TCG generated code.
  */
 #ifdef CONFIG_SOFTMMU
-uint8_t helper_ret_ldb_mmu(CPUArchState *env, target_ulong addr,
-                           int mmu_idx, uintptr_t retaddr);
-uint16_t helper_ret_ldw_mmu(CPUArchState *env, target_ulong addr,
-                            int mmu_idx, uintptr_t retaddr);
-uint32_t helper_ret_ldl_mmu(CPUArchState *env, target_ulong addr,
-                            int mmu_idx, uintptr_t retaddr);
+/* Value zero-extended to tcg register size.  */
+tcg_target_ulong helper_ret_ldub_mmu(CPUArchState *env, target_ulong addr,
+                                     int mmu_idx, uintptr_t retaddr);
+tcg_target_ulong helper_ret_lduw_mmu(CPUArchState *env, target_ulong addr,
+                                     int mmu_idx, uintptr_t retaddr);
+tcg_target_ulong helper_ret_ldul_mmu(CPUArchState *env, target_ulong addr,
+                                     int mmu_idx, uintptr_t retaddr);
 uint64_t helper_ret_ldq_mmu(CPUArchState *env, target_ulong addr,
                             int mmu_idx, uintptr_t retaddr);
 
+/* Value sign-extended to tcg register size.  */
+tcg_target_ulong helper_ret_ldsb_mmu(CPUArchState *env, target_ulong addr,
+                                     int mmu_idx, uintptr_t retaddr);
+tcg_target_ulong helper_ret_ldsw_mmu(CPUArchState *env, target_ulong addr,
+                                     int mmu_idx, uintptr_t retaddr);
+tcg_target_ulong helper_ret_ldsl_mmu(CPUArchState *env, target_ulong addr,
+                                     int mmu_idx, uintptr_t retaddr);
+
 void helper_ret_stb_mmu(CPUArchState *env, target_ulong addr, uint8_t val,
                         int mmu_idx, uintptr_t retaddr);
 void helper_ret_stw_mmu(CPUArchState *env, target_ulong addr, uint16_t val,
-- 
1.8.1.4