[PING] [PATCH] [MSP430] PR79242: Implement Complex Partial Integers

[Jozef Lawrynowicz <jozefl dot gcc at gmail dot com>]

ping x1

Complex Partial Integers are unimplemented, resulting in an ICE when
attempting to use them. https://gcc.gnu.org/bugzilla/show_bug.cgi?id=79242
This results in GCC7/8 for msp430-elf failing to build.

typedef _Complex __int20 C;

C
foo (C x, C y)
{
  return x + y;
}

(Thanks Jakub - https://gcc.gnu.org/bugzilla/show_bug.cgi?id=79242#c2)

../../gcc/testsuite/gcc.target/msp430/pr79242.c: In function 'foo':
../../gcc/testsuite/gcc.target/msp430/pr79242.c:8:1: internal compiler
error: in make_decl_rtl, at varasm.c:1304
 foo (C x, C y)
 ^~~
0xc07b29 make_decl_rtl(tree_node*)
        ../../gcc/varasm.c:1303
0x67523c set_parm_rtl(tree_node*, rtx_def*)
        ../../gcc/cfgexpand.c:1274
0x79ffb9 expand_function_start(tree_node*)
        ../../gcc/function.c:5166
0x6800e1 execute
        ../../gcc/cfgexpand.c:6250

The attached patch defines a new complex mode for PARTIAL_INT.
You may notice that genmodes.c:complex_class returns MODE_COMPLEX_INT for
MODE_PARTIAL_INT rather than MODE_COMPLEX_PARTIAL_INT. I reviewed the uses of
MODE_COMPLEX_INT and it doesn't looked like a Complex Partial Int requires any
different behaviour to MODE_COMPLEX_INT.

msp430_hard_regno_nregs now returns 2 for CPSImode, but I feel like this may be
better handled in the front-end. PSImode is already defined to only use 1
register, so for a CPSI shouldn't the front-end should be able to work out that
double the amount of registers are required? Thoughts?
Without the definition for CPSI in msp430_hard_regno_nregs,
rtlanal.c:subreg_get_info thinks that a CPSI requires 4 registers of size 2,
instead of 2 registers of size 4.

Successfully bootstrapped and tested for c,c++,fortran,lto,objc on
x86_64-pc-linux-gnu with no regressions on gcc-7-branch.

With this patch gcc-7-branch now builds for msp430-elf. A further bug prevents
trunk from building for msp430-elf.

If the attached patch is acceptable, I would appreciate if someone would commit
it for me (to trunk and gcc-7-branch), as I do not have write access.

From 31d8554ebb6afeb2d8f235cf3d3c262236aa5e32 Mon Sep 17 00:00:00 2001
From: Jozef Lawrynowicz <jozefl.gcc@gmail.com>
Date: Fri, 12 Jan 2018 13:23:40 +0000
Subject: [PATCH] Add support for Complex Partial Integers - CPSImode

2018-01-XX  Jozef Lawrynowicz <jozefl.gcc@gmail.com>

gcc/
  PR target/79242
  * machmode.def: Define a complex mode for PARTIAL_INT.
  * genmodes.c (complex_class): Return MODE_COMPLEX_INT for
    MODE_PARTIAL_INT.
  * doc/rtl.texi: Document CSPImode.
  * config/msp430/msp430.c (msp430_hard_regno_nregs): Add CPSImode
    handling.
    (msp430_hard_regno_nregs_with_padding): Likewise.

gcc/testsuite/
  PR target/79242
  * gcc.target/msp430/pr79242.c: New test.
---
 gcc/config/msp430/msp430.c                |  4 ++++
 gcc/doc/rtl.texi                          |  5 +++--
 gcc/genmodes.c                            |  1 +
 gcc/machmode.def                          |  1 +
 gcc/testsuite/gcc.target/msp430/pr79242.c | 11 +++++++++++
 5 files changed, 20 insertions(+), 2 deletions(-)
 create mode 100644 gcc/testsuite/gcc.target/msp430/pr79242.c

diff --git a/gcc/config/msp430/msp430.c b/gcc/config/msp430/msp430.c
index 710a97b..c1f0d5b 100644
--- a/gcc/config/msp430/msp430.c
+++ b/gcc/config/msp430/msp430.c
@@ -905,6 +905,8 @@ msp430_hard_regno_nregs (int regno ATTRIBUTE_UNUSED,
 {
   if (mode == PSImode && msp430x)
     return 1;
+  if (mode == CPSImode && msp430x)
+    return 2;
   return ((GET_MODE_SIZE (mode) + UNITS_PER_WORD - 1)
 	  / UNITS_PER_WORD);
 }
@@ -927,6 +929,8 @@ msp430_hard_regno_nregs_with_padding (int regno ATTRIBUTE_UNUSED,
 {
   if (mode == PSImode)
     return 2;
+  if (mode == CPSImode)
+    return 4;
   return msp430_hard_regno_nregs (regno, mode);
 }
 
diff --git a/gcc/doc/rtl.texi b/gcc/doc/rtl.texi
index b02e5a1..ebe2a63 100644
--- a/gcc/doc/rtl.texi
+++ b/gcc/doc/rtl.texi
@@ -1291,10 +1291,11 @@ point values.  The floating point values are in @code{QFmode},
 @findex CDImode
 @findex CTImode
 @findex COImode
-@item CQImode, CHImode, CSImode, CDImode, CTImode, COImode
+@findex CPSImode
+@item CQImode, CHImode, CSImode, CDImode, CTImode, COImode, CPSImode
 These modes stand for a complex number represented as a pair of integer
 values.  The integer values are in @code{QImode}, @code{HImode},
-@code{SImode}, @code{DImode}, @code{TImode}, and @code{OImode},
+@code{SImode}, @code{DImode}, @code{TImode}, @code{OImode}, and @code{PSImode},
 respectively.
 
 @findex BND32mode
diff --git a/gcc/genmodes.c b/gcc/genmodes.c
index e56c08b..2af6556 100644
--- a/gcc/genmodes.c
+++ b/gcc/genmodes.c
@@ -116,6 +116,7 @@ complex_class (enum mode_class c)
   switch (c)
     {
     case MODE_INT: return MODE_COMPLEX_INT;
+    case MODE_PARTIAL_INT: return MODE_COMPLEX_INT;
     case MODE_FLOAT: return MODE_COMPLEX_FLOAT;
     default:
       error ("no complex class for class %s", mode_class_names[c]);
diff --git a/gcc/machmode.def b/gcc/machmode.def
index afe6851..6c84488 100644
--- a/gcc/machmode.def
+++ b/gcc/machmode.def
@@ -243,6 +243,7 @@ UACCUM_MODE (UTA, 16, 64, 64); /* 64.64 */
 
 /* Complex modes.  */
 COMPLEX_MODES (INT);
+COMPLEX_MODES (PARTIAL_INT);
 COMPLEX_MODES (FLOAT);
 
 /* Decimal floating point modes.  */
diff --git a/gcc/testsuite/gcc.target/msp430/pr79242.c b/gcc/testsuite/gcc.target/msp430/pr79242.c
new file mode 100644
index 0000000..d7ff8d3
--- /dev/null
+++ b/gcc/testsuite/gcc.target/msp430/pr79242.c
@@ -0,0 +1,11 @@
+/* { dg-do compile } */
+/* { dg-skip-if "" { "*-*-*" } { "-mcpu=msp430" "-msmall" } { "" } } */
+/* { dg-options "-mcpu=msp430x" } */
+
+typedef _Complex __int20 C;
+
+C
+foo (C x, C y)
+{
+  return x + y;
+}
-- 
2.7.4