diff options
Diffstat (limited to 'debian/patches/pr94253.diff')
| -rw-r--r-- | debian/patches/pr94253.diff | 48 |
1 files changed, 48 insertions, 0 deletions
diff --git a/debian/patches/pr94253.diff b/debian/patches/pr94253.diff new file mode 100644 index 0000000..ed28ad7 --- /dev/null +++ b/debian/patches/pr94253.diff @@ -0,0 +1,48 @@ +commit 50e1e417b5cc68a6fd280e0a67c5c4eba524b70b +Author: Richard Sandiford <richard.sandiford@arm.com> +Date: Sun Mar 22 18:51:48 2020 +0000 + + rs6000: Allow FPRs to change between SDmode and DDmode [PR94254] + + g:497498c878d48754318e486428e2aa30854020b9 caused lra to cycle + on some SDmode reloads for power6. As explained in more detail + in the PR comments, the problem was a conflict between two target + hooks: rs6000_secondary_memory_needed_mode required SDmode FPR + reloads to use DDmode memory (rightly, since using SDmode memory + wouldn't make progress) but rs6000_can_change_mode_class didn't + allow FPRs to change from SDmode to DDmode. Previously lra + ignored that and changed the mode anyway. + + From what Segher says, it sounds like the "from_size < 8 || to_size < 8" + check is mostly there for SF<->64-bit subregs, and that SDmode is stored + in the way that target-independent code expects. This patch therefore + allows SD<->DD changes. + + I wondered about checking for SD<->64-bit changes instead, but that + seemed like an unnecessary generalisation for this stage. + + 2020-03-23 Richard Sandiford <richard.sandiford@arm.com> + + gcc/ + PR target/94254 + * config/rs6000/rs6000.c (rs6000_can_change_mode_class): Allow + FPRs to change between SDmode and DDmode. + +--- a/src/gcc/config/rs6000/rs6000.cc ++++ b/src/gcc/config/rs6000/rs6000.cc +@@ -13399,6 +13399,15 @@ rs6000_can_change_mode_class (machine_mo + || (to == SDmode && from == DDmode)) + return true; + ++ /* Allow SD<->DD changes, since SDmode values are stored in ++ the low half of the DDmode, just like target-independent ++ code expects. We need to allow at least SD->DD since ++ rs6000_secondary_memory_needed_mode asks for that change ++ to be made for SD reloads. */ ++ if ((to == DDmode && from == SDmode) ++ || (to == SDmode && from == DDmode)) ++ return true; ++ + if (from_size < 8 || to_size < 8) + return false; + |