Re: [Qemu-devel] Compilation broken in SVN version and a debug register question

["Ben Taylor" <bentaylor.solx86@gmail.com>]

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On Wed, Apr 23, 2008 at 8:34 AM, Balazs Attila-Mihaly (Cd-MaN)
<x_at_y_or_z@yahoo.com> wrote:
> Hello all.
>
>  I fail to compile the version 4242 from the SVN (which I checked out ~1 hour ago). On an Ubuntu 7.10 host with gcc-3.4 and ./configure --target-list=i386-softmmu, I get the following error:
>
>  make -C i386-softmmu all
>  make[1]: Entering directory `/home/cdman/qemu/trunk/i386-softmmu'
>  gcc-3.4 -Wall -O2 -g -fno-strict-aliasing  -fno-reorder-blocks  -fno-gcse    -fno-optimize-sibling-calls  -fno-crossjumping  -fno-align-labels  -fno-align-jumps  -fno-align-functions   -mpreferred-stack-boundary=2 -fomit-frame-pointer  -m32 -I. -I.. -I/home/cdman/qemu/trunk/target-i386 -I/home/cdman/qemu/trunk -MMD -MP -DNEED_CPU_H -D_GNU_SOURCE -D_FILE_OFFSET_BITS=64 -D_LARGEFILE_SOURCE -I/home/cdman/qemu/trunk/tcg -I/home/cdman/qemu/trunk/tcg/i386 -I/home/cdman/qemu/trunk/fpu -DHAS_AUDIO -DHAS_AUDIO_CHOICE -I/home/cdman/qemu/trunk/slirp -c -o op.o /home/cdman/qemu/trunk/target-i386/op.c
>  /home/cdman/qemu/trunk/target-i386/ops_sse.h: In function `op_pshufw_mmx':
>  /home/cdman/qemu/trunk/target-i386/ops_sse.h:597: error: unable to find a register to spill in class `GENERAL_REGS'
>  /home/cdman/qemu/trunk/target-i386/ops_sse.h:597: error: this is the insn:
>  (insn:HI 18 17 19 0 /home/cdman/qemu/trunk/target-i386/ops_sse.h:592 (set (strict_low_part (subreg:HI (reg/v:DI 58 [ r ]) 0))
>         (mem/s/j:HI (plus:SI (mult:SI (reg:SI 62)
>                     (const_int 2 [0x2]))
>                 (reg/v/f:SI 60 [ s ])) [0 <variable>._w S2 A16])) 54 {*movstricthi_1} (insn_list 16 (insn_list 12 (insn_list 50 (nil))))
>     (expr_list:REG_DEAD (reg:SI 62)
>         (nil)))
>  /home/cdman/qemu/trunk/target-i386/ops_sse.h:597: confused by earlier errors, bailing out
>  make[1]: *** [op.o] Error 1
>  make[1]: Leaving directory `/home/cdman/qemu/trunk/i386-softmmu'
>  make: *** [subdir-i386-softmmu] Error 2
>
>  Is this related to the recent discussion about MMX/SSE instructions?
>
>  Also, I have a weird behaviour with qemu-0.9.0 (I will test it against the SVN snapshot as soon as I can get it to compile :)). The behavior is related to hardware breakpoints. I use a Linux host and Windows XP guest and in the guest I use a user-mode debugger (Olly - http://ollydbg.de/) to debug a program. Software breakpoints work ok, but hardware breakpoints only work when I run __with__ kqemu (which is really weird, since the usual response for all the problems is "try it without kqemu" :)). Is this a known limitation or a bug? Should the code which sets the debug registers be augmented to flush the TB cache and the dyngen code changed to take into account the value of the debug registers (and raise an exception there)? But if this is the case, why does it work with kqemu enabled?
>
>  Thank you in advance for your time spent answering my questions.
>
>  Best regards.

The following patch should fix the compilation of op.c and helper.c.

This been tested on solaris x86 (32/64 bit) and Ubuntu 7.10 (32-bit).  When
configuring on the 32-bit systems, I used --extra-cflags="-march=i686
-mtune=i686"
and both spill errors in op.c and helper.c are gone, and the binaries
will boot Milax (a Solaris based DamnSmallLinux clone)

Once the sse ops are converted to TCG, I imagine these hacks to the
Makefile.target file can be removed.

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diff -ruN qemu.ORIG/Makefile.target qemu/Makefile.target
--- qemu.ORIG/Makefile.target	2008-05-04 10:42:56.000000000 -0400
+++ qemu/Makefile.target	2008-05-04 12:02:56.068374000 -0400
@@ -96,6 +96,7 @@
 ifeq ($(ARCH),i386)
 HELPER_CFLAGS+=-fomit-frame-pointer
 OP_CFLAGS+=-mpreferred-stack-boundary=2 -fomit-frame-pointer
+MTUNE_CFLAGS=-march=i486 -mtune=i686
 endif
 
 ifeq ($(ARCH),ppc)
@@ -279,6 +280,12 @@
 LIBOBJS+=s390-dis.o
 endif
 
+ifeq ($(ARCH), i386)
+	HCFLAGS=`echo $(CFLAGS) | sed 's,-march=i686,,'`
+else
+	HCFLAGS=$(CFLAGS)
+endif
+
 # libqemu
 
 ifndef CONFIG_NO_DYNGEN_OP
@@ -309,7 +316,7 @@
 	$(DYNGEN) -g -o $@ $<
 
 op.o: op.c
-	$(CC) $(OP_CFLAGS) $(CPPFLAGS) -c -o $@ $<
+	$(CC) $(OP_CFLAGS) $(CPPFLAGS) $(MTUNE_CFLAGS) -c -o $@ $<
 
 machine.o: machine.c
 	$(CC) $(OP_CFLAGS) $(CPPFLAGS) -c -o $@ $<
@@ -319,7 +326,7 @@
 ifeq ($(TARGET_BASE_ARCH), i386)
 # XXX: rename helper.c to op_helper.c
 helper.o: helper.c
-	$(CC) $(HELPER_CFLAGS) $(CPPFLAGS) $(CFLAGS) -c -o $@ $<
+	$(CC) $(HELPER_CFLAGS) $(CPPFLAGS) $(MTUNE_CFLAGS) $(HCFLAGS) -c -o $@ $<
 else
 op_helper.o: op_helper.c
 	$(CC) $(HELPER_CFLAGS) $(CPPFLAGS) $(CFLAGS) -c -o $@ $<