From d0e4968c33c257bcfa1afa4f499661c18c80e5bc Mon Sep 17 00:00:00 2001
From: David Daney <ddaney@caviumnetworks.com>
Date: Fri, 4 Dec 2009 17:46:23 +0000
Subject: [PATCH] re PR rtl-optimization/42164 (internal compiler error: in
simplify_subreg, at simplify-rtx.c:5138)
2009-12-04 David Daney <ddaney@caviumnetworks.com>
PR rtl-optimization/42164
* combine.c (combine_simplify_rtx): Handle truncation of integer
constants.
2009-12-04 David Daney <ddaney@caviumnetworks.com>
PR rtl-optimization/42164
* gcc.c-torture/compile/pr42164.c: New test.
From-SVN: r154987
---
gcc/ChangeLog | 6 +++++
gcc/combine.c | 4 +++
gcc/testsuite/ChangeLog | 5 ++++
gcc/testsuite/gcc.c-torture/compile/pr42164.c | 25 +++++++++++++++++++
4 files changed, 40 insertions(+)
create mode 100644 gcc/testsuite/gcc.c-torture/compile/pr42164.c
diff --git a/gcc/ChangeLog b/gcc/ChangeLog
index 450d54d62740..f01968c789c0 100644
--- a/gcc/ChangeLog
+++ b/gcc/ChangeLog
@@ -1,3 +1,9 @@
+2009-12-04 David Daney <ddaney@caviumnetworks.com>
+
+ PR rtl-optimization/42164
+ * combine.c (combine_simplify_rtx): Handle truncation of integer
+ constants.
+
2009-12-04 Richard Guenther <rguenther@suse.de>
* lto-streamer-out.c (pack_ts_decl_common_value_fields):
diff --git a/gcc/combine.c b/gcc/combine.c
index cdc677d17c73..7f3f6da2cea1 100644
--- a/gcc/combine.c
+++ b/gcc/combine.c
@@ -5156,6 +5156,10 @@ combine_simplify_rtx (rtx x, enum machine_mode op0_mode, int in_dest)
force_to_mode (XEXP (x, 0), GET_MODE (XEXP (x, 0)),
GET_MODE_MASK (mode), 0));
+ /* We can truncate a constant value and return it. */
+ if (CONST_INT_P (XEXP (x, 0)))
+ return gen_int_mode (INTVAL (XEXP (x, 0)), mode);
+
/* Similarly to what we do in simplify-rtx.c, a truncate of a register
whose value is a comparison can be replaced with a subreg if
STORE_FLAG_VALUE permits. */
diff --git a/gcc/testsuite/ChangeLog b/gcc/testsuite/ChangeLog
index 577d18b21633..b20ddd2fdcf5 100644
--- a/gcc/testsuite/ChangeLog
+++ b/gcc/testsuite/ChangeLog
@@ -1,3 +1,8 @@
+2009-12-04 David Daney <ddaney@caviumnetworks.com>
+
+ PR rtl-optimization/42164
+ * gcc.c-torture/compile/pr42164.c: New test.
+
2009-12-04 Eric Botcazou <ebotcazou@adacore.com>
* gnat.dg/specs/size_attribute1.ads: New test.
diff --git a/gcc/testsuite/gcc.c-torture/compile/pr42164.c b/gcc/testsuite/gcc.c-torture/compile/pr42164.c
new file mode 100644
index 000000000000..7b94aefe7d83
--- /dev/null
+++ b/gcc/testsuite/gcc.c-torture/compile/pr42164.c
@@ -0,0 +1,25 @@
+typedef struct
+{
+ unsigned long long pte;
+} pte_t;
+pte_t mk_swap_pte (unsigned long offset)
+{
+ pte_t pte;
+ pte.pte = (offset << 40);
+ return pte;
+}
+int pte_file (pte_t pte)
+{
+ return pte.pte & (1 << 4);
+}
+typedef struct
+{
+ unsigned long val;
+} swp_entry_t;
+pte_t swp_entry_to_pte (swp_entry_t entry)
+{
+ swp_entry_t arch_entry;
+ arch_entry = (swp_entry_t){mk_swap_pte (swp_offset (entry)).pte};
+ __BUG_ON ((unsigned long) pte_file ((pte_t) {arch_entry.val}));
+ return (pte_t) {arch_entry.val};
+}
--
GitLab