[Bug debug/105586] New: [11/12/13 Regression] -fcompare-debug failure (length) with -O2 -fno-if-conversion -mtune=power4 -fno-guess-branch-probability

[zsojka at seznam dot cz]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=105586

            Bug ID: 105586
           Summary: [11/12/13 Regression] -fcompare-debug failure (length)
                    with -O2 -fno-if-conversion -mtune=power4
                    -fno-guess-branch-probability
           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
  Target Milestone: ---
              Host: x86_64-pc-linux-gnu
            Target: powerpc64le-unknown-linux-gnu

Created attachment 52968
  --> https://gcc.gnu.org/bugzilla/attachment.cgi?id=52968&action=edit
reduced testcase

Compiler output:
$ powerpc64le-unknown-linux-gnu-gcc -O2 -fno-if-conversion -mtune=power4
-fno-guess-branch-probability -fcompare-debug testcase.c 
powerpc64le-unknown-linux-gnu-gcc: error: testcase.c: '-fcompare-debug' failure
(length)

$ diff -u *gkd
--- a-testcase.c.gkd    2022-05-12 21:05:45.139502516 +0200
+++ a-testcase.gk.c.gkd 2022-05-12 21:05:45.172835666 +0200
@@ -128,21 +128,23 @@
         (and:SI (reg:SI 10 10 [orig:136 u128_1 ] [136])
             (const_int 8 [0x8]))) "testcase.c":14:78# {andsi3_mask}
      (nil))
-(insn:TI # 0 0 (set (reg:DI 3 3 [orig:161 u64_4 ] [161])
-        (ashift:DI (reg:DI 3 3 [147])
-            (reg:SI 10 10 [160]))) "testcase.c":14:7# {ashldi3}
-     (expr_list:REG_DEAD (reg:SI 10 10 [160])
-        (nil)))
-(insn # 0 0 (set (reg:DI 30 30 [162])
+(insn:TI # 0 0 (set (reg:DI 30 30 [162])
         (plus:DI (reg/v:DI 30 30 [orig:145 b ] [145])
             (reg/v:DI 9 9 [orig:134 u64_3 ] [134]))) "testcase.c":15:17#
{*adddi3}
      (expr_list:REG_DEAD (reg/v:DI 9 9 [orig:134 u64_3 ] [134])
         (nil)))
+(insn # 0 0 (set (reg:DI 9 9 [orig:161 u64_4 ] [161])
+        (ashift:DI (reg:DI 3 3 [147])
+            (reg:SI 10 10 [160]))) "testcase.c":14:7# {ashldi3}
+     (expr_list:REG_DEAD (reg:SI 10 10 [160])
+        (expr_list:REG_DEAD (reg:DI 3 3 [147])
+            (nil))))
 (insn # 0 0 (set (reg:DI 3 3 [orig:163 u64_r ] [163])
-        (plus:DI (reg:DI 3 3 [orig:161 u64_4 ] [161])
+        (plus:DI (reg:DI 9 9 [orig:161 u64_4 ] [161])
             (reg:DI 30 30 [162]))) "testcase.c":15:7# {*adddi3}
      (expr_list:REG_DEAD (reg:DI 30 30 [162])
-        (nil)))
+        (expr_list:REG_DEAD (reg:DI 9 9 [orig:161 u64_4 ] [161])
+            (nil))))
 (insn # 0 0 (set (reg:SI 3 3 [orig:164 u64_r ] [164])
         (sign_extend:SI (reg:HI 3 3 [orig:163 u64_r ] [163])))
"testcase.c":16:7# {*extendhisi2}
      (nil))

$ powerpc64le-unknown-linux-gnu-gcc -v
Using built-in specs.
COLLECT_GCC=/repo/gcc-trunk/binary-latest-powerpc64le/bin/powerpc64le-unknown-linux-gnu-gcc
COLLECT_LTO_WRAPPER=/repo/gcc-trunk/binary-trunk-r13-333-20220511161459-g25addf8352e-checking-yes-rtl-df-extra-powerpc64le/bin/../libexec/gcc/powerpc64le-unknown-linux-gnu/13.0.0/lto-wrapper
Target: powerpc64le-unknown-linux-gnu
Configured with: /repo/gcc-trunk//configure --enable-languages=c,c++
--enable-valgrind-annotations --disable-nls --enable-checking=yes,rtl,df,extra
--with-cloog --with-ppl --with-isl
--with-sysroot=/usr/powerpc64le-unknown-linux-gnu --build=x86_64-pc-linux-gnu
--host=x86_64-pc-linux-gnu --target=powerpc64le-unknown-linux-gnu
--with-ld=/usr/bin/powerpc64le-unknown-linux-gnu-ld
--with-as=/usr/bin/powerpc64le-unknown-linux-gnu-as --disable-libstdcxx-pch
--prefix=/repo/gcc-trunk//binary-trunk-r13-333-20220511161459-g25addf8352e-checking-yes-rtl-df-extra-powerpc64le
Thread model: posix
Supported LTO compression algorithms: zlib zstd
gcc version 13.0.0 20220511 (experimental) (GCC)