tcg/s390/tcg-target.c.inc | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)
The code is currently comparing c2 to the type promotion of
uint32_t and int32_t. That is, the conversion rules are as:
(common_type) c2 == (common_type) (uint32_t)
(is_unsigned
? (uint32_t)c2
: (uint32_t)(int32_t)c2)
In the signed case we lose the desired sign extensions because
of the argument promotion rules of the ternary operator.
Solve the problem by doing the round-trip parsing through the
intermediate type and back to the desired common type (all at
one expression).
Fixes: a534bb15f30 ("tcg/s390: Use constant pool for cmpi")
Reported-by: Miroslav Rezanina <mrezanin@redhat.com>
Reported-by: Richard W.M. Jones <rjones@redhat.com>
Suggested-by: David Hildenbrand <david@redhat.com>
Suggested-by: Eric Blake <eblake@redhat.com>
Signed-off-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
---
tcg/s390/tcg-target.c.inc | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/tcg/s390/tcg-target.c.inc b/tcg/s390/tcg-target.c.inc
index b67470137c4..695d7ee6523 100644
--- a/tcg/s390/tcg-target.c.inc
+++ b/tcg/s390/tcg-target.c.inc
@@ -1067,7 +1067,7 @@ static int tgen_cmp(TCGContext *s, TCGType type, TCGCond c, TCGReg r1,
op = (is_unsigned ? RIL_CLFI : RIL_CFI);
tcg_out_insn_RIL(s, op, r1, c2);
goto exit;
- } else if (c2 == (is_unsigned ? (uint32_t)c2 : (int32_t)c2)) {
+ } else if (c2 == (is_unsigned ? (TCGArg)(uint32_t)c2 : (TCGArg)(int32_t)c2)) {
op = (is_unsigned ? RIL_CLGFI : RIL_CGFI);
tcg_out_insn_RIL(s, op, r1, c2);
goto exit;
--
2.26.2
On 2/4/21 8:29 AM, Philippe Mathieu-Daudé wrote: > The code is currently comparing c2 to the type promotion of > uint32_t and int32_t. That is, the conversion rules are as: > > (common_type) c2 == (common_type) (uint32_t) > (is_unsigned > ? (uint32_t)c2 > : (uint32_t)(int32_t)c2) > > In the signed case we lose the desired sign extensions because > of the argument promotion rules of the ternary operator. > > Solve the problem by doing the round-trip parsing through the > intermediate type and back to the desired common type (all at > one expression). > > Fixes: a534bb15f30 ("tcg/s390: Use constant pool for cmpi") > Reported-by: Miroslav Rezanina <mrezanin@redhat.com> > Reported-by: Richard W.M. Jones <rjones@redhat.com> > Suggested-by: David Hildenbrand <david@redhat.com> > Suggested-by: Eric Blake <eblake@redhat.com> > Signed-off-by: Philippe Mathieu-Daudé <f4bug@amsat.org> > --- > tcg/s390/tcg-target.c.inc | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) A most excellent catch, thanks. Queued. r~
On 04.02.21 19:29, Philippe Mathieu-Daudé wrote: > The code is currently comparing c2 to the type promotion of > uint32_t and int32_t. That is, the conversion rules are as: > > (common_type) c2 == (common_type) (uint32_t) > (is_unsigned > ? (uint32_t)c2 > : (uint32_t)(int32_t)c2) > > In the signed case we lose the desired sign extensions because > of the argument promotion rules of the ternary operator. > > Solve the problem by doing the round-trip parsing through the > intermediate type and back to the desired common type (all at > one expression). > > Fixes: a534bb15f30 ("tcg/s390: Use constant pool for cmpi") > Reported-by: Miroslav Rezanina <mrezanin@redhat.com> > Reported-by: Richard W.M. Jones <rjones@redhat.com> > Suggested-by: David Hildenbrand <david@redhat.com> > Suggested-by: Eric Blake <eblake@redhat.com> > Signed-off-by: Philippe Mathieu-Daudé <f4bug@amsat.org> > --- > tcg/s390/tcg-target.c.inc | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/tcg/s390/tcg-target.c.inc b/tcg/s390/tcg-target.c.inc > index b67470137c4..695d7ee6523 100644 > --- a/tcg/s390/tcg-target.c.inc > +++ b/tcg/s390/tcg-target.c.inc > @@ -1067,7 +1067,7 @@ static int tgen_cmp(TCGContext *s, TCGType type, TCGCond c, TCGReg r1, > op = (is_unsigned ? RIL_CLFI : RIL_CFI); > tcg_out_insn_RIL(s, op, r1, c2); > goto exit; > - } else if (c2 == (is_unsigned ? (uint32_t)c2 : (int32_t)c2)) { > + } else if (c2 == (is_unsigned ? (TCGArg)(uint32_t)c2 : (TCGArg)(int32_t)c2)) { > op = (is_unsigned ? RIL_CLGFI : RIL_CGFI); > tcg_out_insn_RIL(s, op, r1, c2); > goto exit; > Reviewed-by: David Hildenbrand <david@redhat.com> -- Thanks, David / dhildenb
On Thu, Feb 04, 2021 at 07:29:02PM +0100, Philippe Mathieu-Daudé wrote: > The code is currently comparing c2 to the type promotion of > uint32_t and int32_t. That is, the conversion rules are as: > > (common_type) c2 == (common_type) (uint32_t) > (is_unsigned > ? (uint32_t)c2 > : (uint32_t)(int32_t)c2) > > In the signed case we lose the desired sign extensions because > of the argument promotion rules of the ternary operator. > > Solve the problem by doing the round-trip parsing through the > intermediate type and back to the desired common type (all at > one expression). > > Fixes: a534bb15f30 ("tcg/s390: Use constant pool for cmpi") > Reported-by: Miroslav Rezanina <mrezanin@redhat.com> > Reported-by: Richard W.M. Jones <rjones@redhat.com> > Suggested-by: David Hildenbrand <david@redhat.com> > Suggested-by: Eric Blake <eblake@redhat.com> > Signed-off-by: Philippe Mathieu-Daudé <f4bug@amsat.org> > --- > tcg/s390/tcg-target.c.inc | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/tcg/s390/tcg-target.c.inc b/tcg/s390/tcg-target.c.inc > index b67470137c4..695d7ee6523 100644 > --- a/tcg/s390/tcg-target.c.inc > +++ b/tcg/s390/tcg-target.c.inc > @@ -1067,7 +1067,7 @@ static int tgen_cmp(TCGContext *s, TCGType type, TCGCond c, TCGReg r1, > op = (is_unsigned ? RIL_CLFI : RIL_CFI); > tcg_out_insn_RIL(s, op, r1, c2); > goto exit; > - } else if (c2 == (is_unsigned ? (uint32_t)c2 : (int32_t)c2)) { > + } else if (c2 == (is_unsigned ? (TCGArg)(uint32_t)c2 : (TCGArg)(int32_t)c2)) { > op = (is_unsigned ? RIL_CLGFI : RIL_CGFI); > tcg_out_insn_RIL(s, op, r1, c2); > goto exit; I have tested this patch on an s390x host on top of 1ed9228f63e "Merge remote-tracking branch 'remotes/ericb/tags/pull-nbd-2021-02-02-v2' into staging" and I can confirm that it fixes both previously reported problems. Therefore you can add: Tested-by: Richard W.M. Jones <rjones@redhat.com> Rich. -- Richard Jones, Virtualization Group, Red Hat http://people.redhat.com/~rjones Read my programming and virtualization blog: http://rwmj.wordpress.com libguestfs lets you edit virtual machines. Supports shell scripting, bindings from many languages. http://libguestfs.org
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