[Bug debug/107183] New: -fcompare-debug failure (length) with -fsanitize=float-cast-overflow

[zsojka at seznam dot cz via Gcc-bugs]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=107183

            Bug ID: 107183
           Summary: -fcompare-debug failure (length) with
                    -fsanitize=float-cast-overflow
           Product: gcc
           Version: 13.0
            Status: UNCONFIRMED
          Keywords: compare-debug-failure
          Severity: normal
          Priority: P3
         Component: debug
          Assignee: unassigned at gcc dot gnu.org
          Reporter: zsojka at seznam dot cz
                CC: aoliva at gcc dot gnu.org
  Target Milestone: ---
              Host: x86_64-pc-linux-gnu
            Target: x86_64-pc-linux-gnu

Created attachment 53678
  --> https://gcc.gnu.org/bugzilla/attachment.cgi?id=53678&action=edit
reduced testcase

Compiler output:
$ x86_64-pc-linux-gnu-gcc -O -fsanitize=float-cast-overflow -fcompare-debug
testcase.c
x86_64-pc-linux-gnu-gcc: error: testcase.c: '-fcompare-debug' failure (length)
$ diff -u *gkd
--- a-testcase.c.gkd    2022-10-07 20:13:29.246165247 +0200
+++ a-testcase.gk.c.gkd 2022-10-07 20:13:29.299498288 +0200
@@ -79,12 +79,19 @@
         (const_double:SF 0.0 [0x0.0p+0])) "testcase.c":6:18 discrim 2#
{*movsf_internal}
      (expr_list:REG_EQUIV (const_double:SF 0.0 [0x0.0p+0])
         (nil)))
+(insn # 0 0 4 (parallel [
+            (set (reg:XF 9 st(1))
+                (reg:XF 8 st))
+            (set (reg:XF 8 st)
+                (reg:XF 9 st(1)))
+        ]) "testcase.c":6:18 discrim 2# {*swapxf}
+     (nil))
 (insn # 0 0 4 (set (reg:CCFP 17 flags)
         (unspec:CCFP [
                 (compare:CCFP (reg:XF 8 st)
                     (reg:XF 9 st(1)))
             ] UNSPEC_NOTRAP)) "testcase.c":6:18 discrim 2# {*cmpiuxf_i387}
-     (expr_list:REG_DEAD (reg:XF 8 st)
+     (expr_list:REG_DEAD (reg:XF 8 st [107])
         (nil)))
 (insn # 0 0 4 (set (reg:XF 8 st)
         (reg:XF 8 st)) "testcase.c":6:18 discrim 2# {*movxf_internal}


$ x86_64-pc-linux-gnu-gcc -v
Using built-in specs.
COLLECT_GCC=/repo/gcc-trunk/binary-latest-amd64/bin/x86_64-pc-linux-gnu-gcc
COLLECT_LTO_WRAPPER=/repo/gcc-trunk/binary-trunk-r13-3161-20221007142737-g89228e3985c-checking-yes-rtl-df-extra-nobootstrap-amd64/bin/../libexec/gcc/x86_64-pc-linux-gnu/13.0.0/lto-wrapper
Target: x86_64-pc-linux-gnu
Configured with: /repo/gcc-trunk//configure --enable-languages=c,c++
--enable-valgrind-annotations --disable-nls --enable-checking=yes,rtl,df,extra
--disable-bootstrap --with-cloog --with-ppl --with-isl
--build=x86_64-pc-linux-gnu --host=x86_64-pc-linux-gnu
--target=x86_64-pc-linux-gnu --with-ld=/usr/bin/x86_64-pc-linux-gnu-ld
--with-as=/usr/bin/x86_64-pc-linux-gnu-as --disable-libstdcxx-pch
--prefix=/repo/gcc-trunk//binary-trunk-r13-3161-20221007142737-g89228e3985c-checking-yes-rtl-df-extra-nobootstrap-amd64
Thread model: posix
Supported LTO compression algorithms: zlib zstd
gcc version 13.0.0 20221007 (experimental) (GCC)