* config/c4x/c4x.c (c4x_expand_prologue): Don't compile an ISR

	with more than 32767 words of local storage.

git-svn-id: svn+ssh://gcc.gnu.org/svn/gcc/trunk@38703 138bc75d-0d04-0410-961f-82ee72b054a4

diff --git a/gcc/ChangeLog b/gcc/ChangeLog
index a710137..fd4905a 100644 (file)
--- a/gcc/ChangeLog
+++ b/gcc/ChangeLog
@@ -1,5 +1,10 @@
 2001-01-05  Michael Hayes  <m.hayes@elec.canterbury.ac.nz>
 
+       * config/c4x/c4x.c (c4x_expand_prologue): Don't compile an ISR
+       with more than 32767 words of local storage.
+
+2001-01-05  Michael Hayes  <m.hayes@elec.canterbury.ac.nz>
+
        * config/c4x/c4x.c (c4x_init_builtins): Remove builtin support
        for 'abs', 'labs', and 'fabs'.
        (c4x_expand_builtin): Likewise.

diff --git a/gcc/config/c4x/c4x.c b/gcc/config/c4x/c4x.c
index 230b54c..496da47 100644 (file)
--- a/gcc/config/c4x/c4x.c
+++ b/gcc/config/c4x/c4x.c
@@ -826,10 +826,15 @@ c4x_expand_prologue ()
          insn = emit_insn (gen_movqi (gen_rtx_REG (QImode, AR3_REGNO),
                                       gen_rtx_REG (QImode, SP_REGNO)));
           RTX_FRAME_RELATED_P (insn) = 1;
-         /* FIXME: Assume ISR doesn't require more than 32767 words
-            of local variables.  */
+         /* We require that an ISR uses fewer than 32768 words of
+            local variables, otherwise we have to go to lots of
+            effort to save a register, load it with the desired size,
+            adjust the stack pointer, and then restore the modified
+            register.  Frankly, I think it is a poor ISR that
+            requires more than 32767 words of local temporary
+            storage!  */
          if (size > 32767)
-           error ("ISR %s requires %d words of local vars, max is 32767.",
+           fatal ("ISR %s requires %d words of local vars, max is 32767.",
                   current_function_name, size);
          insn = emit_insn (gen_addqi3 (gen_rtx_REG (QImode, SP_REGNO),
                                        gen_rtx_REG (QImode, SP_REGNO),