Bug#579780: powerpcspe: Preliminary architecture port and minor bugfix

To: Debian Bug Tracking System <submit@bugs.debian.org>
Subject: Bug#579780: powerpcspe: Preliminary architecture port and minor bugfix
From: Kyle Moffett <Kyle.D.Moffett@boeing.com>
Date: Fri, 30 Apr 2010 13:48:32 -0400
Message-id: <[🔎] 20100430174832.7212.27896.reportbug@philyra.exmeritus.com>
Reply-to: Kyle Moffett <Kyle.D.Moffett@boeing.com>, 579780@bugs.debian.org

Package: gcc-4.4
Version: 4.4.2-9
Severity: normal
Tags: sid patch

The 'powerpcspe' architecture is a binary-incompatible variant of
PowerPC/POWER designed and supported by FreeScale and IBM.  It is also
known under the trade names "e500"/"MPC8500" and "e200"/"MPC5xx".

This architecture was added to dpkg in commit feb5792 on 2010/04/30:
  http://git.debian.org/?p=dpkg/dpkg.git;a=commitdiff;h=feb5792

Additional information can be found at:
  http://en.wikipedia.org/wiki/PowerPC_e500
  http://en.wikipedia.org/wiki/PowerPC_e200

In particular, the 'powerpcspe' architecture lacks the classic FPU with
dedicated FPRs found on most other PowerPC systems.  It is replaced with
a set of "SPE" instructions which perform floating-point operations on
the integer registers.

In an unfortunate choice of architecture design, the instructions used
for the "SPE" operations overlap with those for the AltiVec unit on most
other modern PowerPC cores.

The "e500v2"-series chips have 64-bit GPRs, where the high 32-bits are
accesible only via the special "SPE" instructions, allowing them to make
efficient use of the "double" datatype.

The relative rare "e500v1"-series chips have only 32-bit GPRs, and
require software traps and emulation to support native "double".

The "e200z3" and "e200z6" chips have no support for floating point at
all, but with software traps and emulation are binary-compatible with
the "e500"-series chips.

The Debian port to this architecture specifically chooses to optimize
for the higher-end chips (e500v2), as most of the others are targeted at
automotive applications or no longer in production.

GCC by default builds correctly with full support for the e500v2 as long
as the following options are passed to "configure":
  --with-cpu=8548
  --enable-e500_double
  --with-long-double-128

The only changes needed are to extend a few matches on "powerpc ppc64"
to also match "powerpcspe" to ensure that we include essential headers.
One of those headers in particular (spe.h) is necessary to successfully
build EGLIBC's floating-point support.

At this time the 'powerpcspe' architecture port is still very much an
unofficial port.  While we hope that will change in the future, it is
entirely possible that the embedded niche of the processor will make
such an official Debian port problematic.

Signed-off-by: Kyle Moffett <Kyle.D.Moffett@boeing.com>
---
 debian/rules.d/binary-gcc-cross.mk |    4 ++--
 debian/rules.d/binary-gcc.mk       |    2 +-
 debian/rules.d/binary-java.mk      |    2 +-
 debian/rules2                      |    4 ++++
 4 files changed, 8 insertions(+), 4 deletions(-)

diff --git a/debian/rules.d/binary-gcc-cross.mk b/debian/rules.d/binary-gcc-cross.mk
index a39e84f..b642ba2 100644
--- a/debian/rules.d/binary-gcc-cross.mk
+++ b/debian/rules.d/binary-gcc-cross.mk
@@ -71,8 +71,8 @@ ifeq ($(DEB_TARGET_ARCH),m68k)
     files_gcc += $(gcc_lib_dir)/include/math-68881.h
 endif
 
-ifeq ($(DEB_TARGET_ARCH),$(findstring $(DEB_TARGET_ARCH),powerpc ppc64))
-    files_gcc += $(gcc_lib_dir)/include/{altivec.h,ppc-asm.h}
+ifeq ($(DEB_TARGET_ARCH),$(findstring $(DEB_TARGET_ARCH),powerpc ppc64 powerpcspe))
+    files_gcc += $(gcc_lib_dir)/include/{altivec.h,ppc-asm.h,spe.h}
 endif
 
 usr_doc_files = debian/README.Bugs \
diff --git a/debian/rules.d/binary-gcc.mk b/debian/rules.d/binary-gcc.mk
index 55af73b..20e36ff 100644
--- a/debian/rules.d/binary-gcc.mk
+++ b/debian/rules.d/binary-gcc.mk
@@ -74,7 +74,7 @@ ifeq ($(DEB_HOST_ARCH),m68k)
     files_gcc += $(gcc_lib_dir)/include/math-68881.h
 endif
 
-ifeq ($(DEB_TARGET_ARCH),$(findstring $(DEB_TARGET_ARCH),powerpc ppc64))
+ifeq ($(DEB_TARGET_ARCH),$(findstring $(DEB_TARGET_ARCH),powerpc ppc64 powerpcspe))
     files_gcc += $(gcc_lib_dir)/include/{altivec.h,ppc-asm.h,spe.h}
 endif
 
diff --git a/debian/rules.d/binary-java.mk b/debian/rules.d/binary-java.mk
index 7f0249a..f2b9f94 100644
--- a/debian/rules.d/binary-java.mk
+++ b/debian/rules.d/binary-java.mk
@@ -236,7 +236,7 @@ ifeq ($(with_standalone_gcj),yes)
     files_gcj += $(gcc_lib_dir)/include/math-68881.h
   endif
 
-  ifeq ($(DEB_TARGET_ARCH),$(findstring $(DEB_TARGET_ARCH),powerpc ppc64))
+  ifeq ($(DEB_TARGET_ARCH),$(findstring $(DEB_TARGET_ARCH),powerpc ppc64 powerpcspe))
     files_gcj += $(gcc_lib_dir)/include/{altivec.h,ppc-asm.h,spe.h}
   endif
 
diff --git a/debian/rules2 b/debian/rules2
index 252c671..01bbbca 100644
--- a/debian/rules2
+++ b/debian/rules2
@@ -260,6 +260,10 @@ ifneq (,$(findstring powerpc-linux,$(DEB_TARGET_GNU_TYPE)))
     endif
 endif
 
+ifeq ($(findstring powerpcspe,$(DEB_TARGET_ARCH)),powerpcspe)
+  CONFARGS += --with-cpu=8548 --enable-e500_double --with-long-double-128
+endif
+
 ifneq (,$(findstring softfloat,$(DEB_TARGET_GNU_CPU)))
   CONFARGS += --with-float=soft
 endif
-- 
1.7.0

--- Begin Message ---

Subject: [PATCH 2/2] powerpcspe: Preliminary architecture port and minor bugfix
From: Kyle Moffett <Kyle.D.Moffett@boeing.com>
Date: Tue, 23 Mar 2010 15:10:18 -0400

The 'powerpcspe' architecture is a binary-incompatible variant of
PowerPC/POWER designed and supported by FreeScale and IBM.  It is also
known under the trade names "e500"/"MPC8500" and "e200"/"MPC5xx".

This architecture was added to dpkg in commit feb5792 on 2010/04/30:
  http://git.debian.org/?p=dpkg/dpkg.git;a=commitdiff;h=feb5792

Additional information can be found at:
  http://en.wikipedia.org/wiki/PowerPC_e500
  http://en.wikipedia.org/wiki/PowerPC_e200

In particular, the 'powerpcspe' architecture lacks the classic FPU with
dedicated FPRs found on most other PowerPC systems.  It is replaced with
a set of "SPE" instructions which perform floating-point operations on
the integer registers.

In an unfortunate choice of architecture design, the instructions used
for the "SPE" operations overlap with those for the AltiVec unit on most
other modern PowerPC cores.

The "e500v2"-series chips have 64-bit GPRs, where the high 32-bits are
accesible only via the special "SPE" instructions, allowing them to make
efficient use of the "double" datatype.

The relative rare "e500v1"-series chips have only 32-bit GPRs, and
require software traps and emulation to support native "double".

The "e200z3" and "e200z6" chips have no support for floating point at
all, but with software traps and emulation are binary-compatible with
the "e500"-series chips.

The Debian port to this architecture specifically chooses to optimize
for the higher-end chips (e500v2), as most of the others are targeted at
automotive applications or no longer in production.

GCC by default builds correctly with full support for the e500v2 as long
as the following options are passed to "configure":
  --with-cpu=8548
  --enable-e500_double
  --with-long-double-128

The only changes needed are to extend a few matches on "powerpc ppc64"
to also match "powerpcspe" to ensure that we include essential headers.
One of those headers in particular (spe.h) is necessary to successfully
build EGLIBC's floating-point support.

At this time the 'powerpcspe' architecture port is still very much an
unofficial port.  While we hope that will change in the future, it is
entirely possible that the embedded niche of the processor will make
such an official Debian port problematic.

Signed-off-by: Kyle Moffett <Kyle.D.Moffett@boeing.com>
---
 debian/rules.d/binary-gcc-cross.mk |    4 ++--
 debian/rules.d/binary-gcc.mk       |    2 +-
 debian/rules.d/binary-java.mk      |    2 +-
 debian/rules2                      |    4 ++++
 4 files changed, 8 insertions(+), 4 deletions(-)

diff --git a/debian/rules.d/binary-gcc-cross.mk b/debian/rules.d/binary-gcc-cross.mk
index a39e84f..b642ba2 100644
--- a/debian/rules.d/binary-gcc-cross.mk
+++ b/debian/rules.d/binary-gcc-cross.mk
@@ -71,8 +71,8 @@ ifeq ($(DEB_TARGET_ARCH),m68k)
     files_gcc += $(gcc_lib_dir)/include/math-68881.h
 endif
 
-ifeq ($(DEB_TARGET_ARCH),$(findstring $(DEB_TARGET_ARCH),powerpc ppc64))
-    files_gcc += $(gcc_lib_dir)/include/{altivec.h,ppc-asm.h}
+ifeq ($(DEB_TARGET_ARCH),$(findstring $(DEB_TARGET_ARCH),powerpc ppc64 powerpcspe))
+    files_gcc += $(gcc_lib_dir)/include/{altivec.h,ppc-asm.h,spe.h}
 endif
 
 usr_doc_files = debian/README.Bugs \
diff --git a/debian/rules.d/binary-gcc.mk b/debian/rules.d/binary-gcc.mk
index 55af73b..20e36ff 100644
--- a/debian/rules.d/binary-gcc.mk
+++ b/debian/rules.d/binary-gcc.mk
@@ -74,7 +74,7 @@ ifeq ($(DEB_HOST_ARCH),m68k)
     files_gcc += $(gcc_lib_dir)/include/math-68881.h
 endif
 
-ifeq ($(DEB_TARGET_ARCH),$(findstring $(DEB_TARGET_ARCH),powerpc ppc64))
+ifeq ($(DEB_TARGET_ARCH),$(findstring $(DEB_TARGET_ARCH),powerpc ppc64 powerpcspe))
     files_gcc += $(gcc_lib_dir)/include/{altivec.h,ppc-asm.h,spe.h}
 endif
 
diff --git a/debian/rules.d/binary-java.mk b/debian/rules.d/binary-java.mk
index 7f0249a..f2b9f94 100644
--- a/debian/rules.d/binary-java.mk
+++ b/debian/rules.d/binary-java.mk
@@ -236,7 +236,7 @@ ifeq ($(with_standalone_gcj),yes)
     files_gcj += $(gcc_lib_dir)/include/math-68881.h
   endif
 
-  ifeq ($(DEB_TARGET_ARCH),$(findstring $(DEB_TARGET_ARCH),powerpc ppc64))
+  ifeq ($(DEB_TARGET_ARCH),$(findstring $(DEB_TARGET_ARCH),powerpc ppc64 powerpcspe))
     files_gcj += $(gcc_lib_dir)/include/{altivec.h,ppc-asm.h,spe.h}
   endif
 
diff --git a/debian/rules2 b/debian/rules2
index 252c671..01bbbca 100644
--- a/debian/rules2
+++ b/debian/rules2
@@ -260,6 +260,10 @@ ifneq (,$(findstring powerpc-linux,$(DEB_TARGET_GNU_TYPE)))
     endif
 endif
 
+ifeq ($(findstring powerpcspe,$(DEB_TARGET_ARCH)),powerpcspe)
+  CONFARGS += --with-cpu=8548 --enable-e500_double --with-long-double-128
+endif
+
 ifneq (,$(findstring softfloat,$(DEB_TARGET_GNU_CPU)))
   CONFARGS += --with-float=soft
 endif
-- 
1.7.0

--- End Message ---

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Follow-Ups:
- Bug#579780: powerpcspe: Preliminary architecture port and minor bugfix
  - From: Sebastian Andrzej Siewior <sebastian@breakpoint.cc>

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