arc: check if the addend fits when referencing small data memory [PR115650]

This prevents linker errors when referencing small data using large
offsets. In practice it is very unlikely to be a real problem but this
was fixed because other compilers do this check and it ensures the
following tests now succeed:
- gcc.dg/torture/pr60115.c
- gcc.dg/torture/pr105665.c

gcc/ChangeLog:

	PR target/115650
	* config/arc/arc.cc (legitimate_small_data_address_p): Check
	offset size.

gcc/testsuite/ChangeLog:

	PR target/115650
	* gcc.target/arc/sdata-6.c: New test.

Signed-off-by: Michiel Derhaeg <michiel@synopsys.com>
Signed-off-by: Claudiu Zissulescu <claziss@gmail.com>

diff --git a/gcc/config/arc/arc.cc b/gcc/config/arc/arc.cc
index a46741b08dc778313e4bf78dbd5ed2caf2e32e40..fd780ea0415f997913e83eaa68981313d964e608 100644 (file)
--- a/gcc/config/arc/arc.cc
+++ b/gcc/config/arc/arc.cc
@@ -386,27 +386,41 @@ legitimate_small_data_address_p (rtx x, machine_mode mode)
       return SYMBOL_REF_SMALL_P (x);
     case PLUS:
       {
-       bool p0 = (GET_CODE (XEXP (x, 0)) == SYMBOL_REF)
-         && SYMBOL_REF_SMALL_P (XEXP (x, 0));
+       if ((GET_CODE (XEXP (x, 0)) != SYMBOL_REF)
+           || !SYMBOL_REF_SMALL_P (XEXP (x, 0)))
+         return false;
 
        /* If no constant then we cannot do small data.  */
        if (!CONST_INT_P (XEXP (x, 1)))
          return false;
 
-       /* Small data relocs works with scalled addresses, check if
+       const int offset = INTVAL (XEXP (x, 1));
+       int size = GET_MODE_SIZE (mode);
+       size = size == 8 ? 4 : size;
+
+       /* Small data relocs works with scaled addresses, check if
           the immediate fits the requirements.  */
-       switch (GET_MODE_SIZE (mode))
+       switch (size)
          {
          case 1:
-           return p0;
+           break;
          case 2:
-           return p0 && ((INTVAL (XEXP (x, 1)) & 0x1) == 0);
+           if ((offset & 0x1) == 0)
+             break;
+           else
+             return false;
          case 4:
-         case 8:
-           return p0 && ((INTVAL (XEXP (x, 1)) & 0x3) == 0);
+           if ((offset & 0x3) == 0)
+             break;
+           else
+             return false;
          default:
            return false;
          }
+
+       /* Reloc allows scaled signed 9 bits.  */
+       const int v = (offset / size) >> 8;
+       return v == 0 || v == -1;
       }
     default:
       return false;

diff --git a/gcc/testsuite/gcc.target/arc/sdata-6.c b/gcc/testsuite/gcc.target/arc/sdata-6.c
new file mode 100644 (file)
index 0000000..2be2617
--- /dev/null
+++ b/gcc/testsuite/gcc.target/arc/sdata-6.c
@@ -0,0 +1,49 @@
+/* { dg-do compile } */
+/* { dg-options "-O2 -msdata" } */
+
+#include <stdint.h>
+
+__attribute__((section(".sdata"))) int a[300];
+
+#define TEST(optype, threshold)                                                \
+  void consume##optype (int, int, int, int, optype);                           \
+  optype test_r0_fit_##optype (void) {                                         \
+    return ((optype *)a)[threshold];                                           \
+  }                                                                            \
+  optype test_r0_no_fit_##optype (void)                                        \
+  {                                                                            \
+    return ((optype *)a)[threshold + 1];                                       \
+  }                                                                            \
+  void test_r4_fit_##optype (void)                                             \
+  {                                                                            \
+    return consume##optype (0, 0, 0, 0, ((optype *)a)[threshold]);             \
+  }                                                                            \
+  void test_r4_no_fit_##optype (void)                                          \
+  {                                                                            \
+    return consume##optype (0, 0, 0, 0, ((optype *)a)[threshold + 1]);         \
+  }
+
+TEST (char,    255)
+TEST (short,   255)
+TEST (int,     255)
+TEST (int64_t, 127)
+
+/* { dg-final { scan-assembler "ldb_s\\s+r0,\\\[gp,@a@sda\\+255\\\]" } } */
+/* { dg-final { scan-assembler "ldb\\s+r0,\\\[@a\\+256\\\]" } } */
+/* { dg-final { scan-assembler "ldb\\s+r4,\\\[gp,@a@sda\\+255\\\]" } } */
+/* { dg-final { scan-assembler "ldb\\s+r4,\\\[@a\\+256\\\]" } } */
+
+/* { dg-final { scan-assembler "ld\[hw\].x.as\\s+r0,\\\[gp,@a@sda\\+510\\\]" } } */
+/* { dg-final { scan-assembler "ld\[hw\].x\\s+r0,\\\[@a\\+512\\\]" } } */
+/* { dg-final { scan-assembler "ld\[hw\].x.as\\s+r4,\\\[gp,@a@sda\\+510\\\]" } } */
+/* { dg-final { scan-assembler "ld\[hw\].x\\s+r4,\\\[@a\\+512\\\]" } } */
+
+/* { dg-final { scan-assembler "ld_s\\s+r0,\\\[gp,@a@sda\\+1020\\\]" } } */
+/* { dg-final { scan-assembler "ld\\s+r0,\\\[@a\\+1024\\\]" } } */
+/* { dg-final { scan-assembler "ld.as\\s+r4,\\\[gp,@a@sda\\+1020\\\]" } } */
+/* { dg-final { scan-assembler "ld\\s+r4,\\\[@a\\+1024\\\]" } } */
+
+/* { dg-final { scan-assembler "ldd.as\\s+r0,\\\[gp,@a@sda\\+1016\\\]" { target ll64} } } */
+/* { dg-final { scan-assembler "ldd\\s+r0,\\\[@a\\+1024\\\]" { target ll64} } } */
+/* { dg-final { scan-assembler "ldd.as\\s+r4,\\\[gp,@a@sda\\+1016\\\]" { target ll64} } } */
+/* { dg-final { scan-assembler "ldd\\s+r4,\\\[@a\\+1024\\\]" { target ll64} } } */