[PATCH][MIPS] Fix ICE for constant pool data in GP area for MIPS16

[Robert Suchanek]

Hi,

The patch fixes an ICE when the compiler tries to split an instruction.
Test attached.

No regression. Ok to apply?

Regards,
Robert

gcc/

2016-05-20  Andrew Bennett  <andrew.benn...@imgtec.com>

        * config/mips/mips.c (mips_constant_pool_symbol_in_sdata_p): New
        function.
        (mips_output_move): Copy GP instead of splitting HIGH when
        accessing constant pool data.

gcc/testsuite/

2016-05-20  Robert Suchanek  <robert.sucha...@imgtec.com>

        * gcc.target/mips/mips16-gp-bug-1.c: New test.
---
 gcc/config/mips/mips.c                          | 20 +++++++++++++++++++-
 gcc/testsuite/gcc.target/mips/mips16-gp-bug-1.c | 12 ++++++++++++
 2 files changed, 31 insertions(+), 1 deletion(-)
 create mode 100644 gcc/testsuite/gcc.target/mips/mips16-gp-bug-1.c

diff --git a/gcc/config/mips/mips.c b/gcc/config/mips/mips.c
index cbe1007..e6d8f76 100644
--- a/gcc/config/mips/mips.c
+++ b/gcc/config/mips/mips.c
@@ -5053,6 +5053,18 @@ mips_split_move_insn (rtx dest, rtx src, rtx insn)
   mips_split_move (dest, src, mips_insn_split_type (insn));
 }
 

+/* Return true if X is a GP-relative symbol in the constant pool.
+   CONTEXT is the context in which X appears.  */
+
+bool
+mips_constant_pool_symbol_in_sdata_p (rtx x, enum mips_symbol_context context)
+{
+  enum mips_symbol_type symbol_type;
+  return (mips_symbolic_constant_p (x, context, &symbol_type)
+         && symbol_type == SYMBOL_GP_RELATIVE
+         && CONSTANT_POOL_ADDRESS_P (x));
+}
+
 /* Return the appropriate instructions to move SRC into DEST.  Assume
    that SRC is operand 1 and DEST is operand 0.  */
 
@@ -5202,7 +5214,13 @@ mips_output_move (rtx dest, rtx src)
        }
 
       if (src_code == HIGH)
-       return TARGET_MIPS16 ? "#" : "lui\t%0,%h1";
+       {
+         if (mips_constant_pool_symbol_in_sdata_p (XEXP (src, 0),
+                                                   SYMBOL_CONTEXT_MEM))
+           return "move\t%0,$28";
+
+         return TARGET_MIPS16 ? "#" : "lui\t%0,%h1";
+       }
 
       if (CONST_GP_P (src))
        return "move\t%0,%1";
diff --git a/gcc/testsuite/gcc.target/mips/mips16-gp-bug-1.c 
b/gcc/testsuite/gcc.target/mips/mips16-gp-bug-1.c
new file mode 100644
index 0000000..85a6d83
--- /dev/null
+++ b/gcc/testsuite/gcc.target/mips/mips16-gp-bug-1.c
@@ -0,0 +1,12 @@
+/* { dg-options "(-mips16) -G4 -mno-abicalls -mcode-readable=no" } */
+typedef struct { int a, b, c, d; } A[5000];
+int a, b;
+extern void bar (int, int, A);
+
+void
+foo (int p1)
+{
+  A c;
+  while (p1)
+    bar (a, b, c);
+}
-- 
2.8.2.396.g5fe494c