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authorVladimir N. Makarov <vmakarov@redhat.com>2021-04-14 13:21:40 -0400
committerVladimir N. Makarov <vmakarov@redhat.com>2021-04-14 13:22:41 -0400
commitf99f64f69db49ce6343d79a39eab28dcc6b91865 (patch)
treea95377d136f83e701a5aadea095055ffd5bff60f /gcc
parent785209fc464ee3efec2b2a8e8244b7292c251ad8 (diff)
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[PR100066] Check paradoxical subreg when splitting hard reg live range
When splitting live range of a hard reg, LRA actually split multi-register containing the hard reg. So we need to check the biggest used mode of the hard reg on paradoxical subregister when the natural and the biggest mode are ordered. gcc/ChangeLog: PR rtl-optimization/100066 * lra-constraints.c (split_reg): Check paradoxical_subreg_p for ordered modes when choosing splitting mode for hard reg. gcc/testsuite/ChangeLog: PR rtl-optimization/100066 * gcc.target/i386/pr100066.c: New.
Diffstat (limited to 'gcc')
-rw-r--r--gcc/lra-constraints.c12
-rw-r--r--gcc/testsuite/gcc.target/i386/pr100066.c13
2 files changed, 21 insertions, 4 deletions
diff --git a/gcc/lra-constraints.c b/gcc/lra-constraints.c
index 62bcfc3..9425f2d 100644
--- a/gcc/lra-constraints.c
+++ b/gcc/lra-constraints.c
@@ -5797,10 +5797,14 @@ split_reg (bool before_p, int original_regno, rtx_insn *insn,
mode = lra_reg_info[hard_regno].biggest_mode;
machine_mode reg_rtx_mode = GET_MODE (regno_reg_rtx[hard_regno]);
/* A reg can have a biggest_mode of VOIDmode if it was only ever seen as
- part of a multi-word register. In that case, just use the reg_rtx.
- Otherwise, limit the size to that of the biggest access in the
- function. */
- if (mode == VOIDmode)
+ part of a multi-word register. In that case, just use the reg_rtx
+ mode. Do the same also if the biggest mode was larger than a register
+ or we can not compare the modes. Otherwise, limit the size to that of
+ the biggest access in the function. */
+ if (mode == VOIDmode
+ || !ordered_p (GET_MODE_PRECISION (mode),
+ GET_MODE_PRECISION (reg_rtx_mode))
+ || paradoxical_subreg_p (mode, reg_rtx_mode))
{
original_reg = regno_reg_rtx[hard_regno];
mode = reg_rtx_mode;
diff --git a/gcc/testsuite/gcc.target/i386/pr100066.c b/gcc/testsuite/gcc.target/i386/pr100066.c
new file mode 100644
index 0000000..a795864
--- /dev/null
+++ b/gcc/testsuite/gcc.target/i386/pr100066.c
@@ -0,0 +1,13 @@
+/* { dg-do compile { target { int128 } } } */
+/* { dg-options "-O1 -w" } */
+int pm;
+
+void
+w3 (int, int, int);
+
+void
+e6 (__int128 rt, long int mo)
+{
+ mo += rt / 0;
+ w3 (pm / mo, pm, 0);
+}