From 978ec4825c2e5cb0ec03d857ea038440d566ff42 Mon Sep 17 00:00:00 2001
From: Jiufu Guo <guojiufu@linux.ibm.com>
Date: Tue, 19 Jul 2022 18:30:58 +0800
Subject: [PATCH] rs6000: cannot_force_const_mem for HIGH code rtx[PR106460]
As the issue in PR106460, a rtx 'high:DI (symbol_ref:DI ("var_48")' is tried
to store into constant pool and ICE occur. But actually, this rtx represents
partial incomplete address and can not be put into a .rodata section.
This patch updates rs6000_cannot_force_const_mem to return true for rtx(s) with
HIGH code, because these rtx(s) indicate part of address and are not ok for
constant pool.
Below are some examples:
(high:DI (const:DI (plus:DI (symbol_ref:DI ("xx") (const_int 12 [0xc])))))
(high:DI (symbol_ref:DI ("var_1")..)))
PR target/106460
gcc/ChangeLog:
* config/rs6000/rs6000.cc (rs6000_cannot_force_const_mem): Return true
for HIGH code rtx.
gcc/testsuite/ChangeLog:
* gcc.target/powerpc/pr106460.c: New test.
---
gcc/config/rs6000/rs6000.cc | 7 +++++--
gcc/testsuite/gcc.target/powerpc/pr106460.c | 12 ++++++++++++
2 files changed, 17 insertions(+), 2 deletions(-)
create mode 100644 gcc/testsuite/gcc.target/powerpc/pr106460.c
diff --git a/gcc/config/rs6000/rs6000.cc b/gcc/config/rs6000/rs6000.cc
index 01e5bbcf0b69..a85d7630b41d 100644
--- a/gcc/config/rs6000/rs6000.cc
+++ b/gcc/config/rs6000/rs6000.cc
@@ -9759,8 +9759,11 @@ rs6000_init_stack_protect_guard (void)
static bool
rs6000_cannot_force_const_mem (machine_mode mode ATTRIBUTE_UNUSED, rtx x)
{
- if (GET_CODE (x) == HIGH
- && GET_CODE (XEXP (x, 0)) == UNSPEC)
+ /* If GET_CODE (x) is HIGH, the 'X' represets the high part of a symbol_ref.
+ It can not be put into a constant pool. e.g.
+ (high:DI (unspec:DI [(symbol_ref/u:DI ("*.LC0")..)
+ (high:DI (symbol_ref:DI ("var")..)). */
+ if (GET_CODE (x) == HIGH)
return true;
/* A TLS symbol in the TOC cannot contain a sum. */
diff --git a/gcc/testsuite/gcc.target/powerpc/pr106460.c b/gcc/testsuite/gcc.target/powerpc/pr106460.c
new file mode 100644
index 000000000000..aae4b015bbaa
--- /dev/null
+++ b/gcc/testsuite/gcc.target/powerpc/pr106460.c
@@ -0,0 +1,12 @@
+/* { dg-require-effective-target power10_ok } */
+/* { dg-options "-O1 -mdejagnu-cpu=power10" } */
+
+/* (high:DI (symbol_ref:DI ("var_48")..))) should not cause ICE. */
+extern short var_48;
+void
+foo (double *r)
+{
+ if (var_48)
+ *r = 1234.5678;
+}
+
--
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