Volatile memory does not match the memory_operand predicate. This
causes extra extend/mask instructions instructions when reading
from volatile memory. On OpenRISC loading volitile memory can be
treated the same as regular memory loads which supports combined
sign/zero extends. Fixing this eliminates the need for extra
extend/mask instructions.
This also adds a test provided by Richard Selvaggi which uncovered the
issue while we were looking into another issue.
gcc/ChangeLog:
PR target/90363
* config/or1k/or1k.md (zero_extend<mode>si2): Update predicate.
(extend<mode>si2): Update predicate.
* gcc/config/or1k/predicates.md (volatile_mem_operand): New.
(reg_or_mem_operand): New.
gcc/testsuite/ChangeLog:
PR target/90363
* gcc.target/or1k/swap-1.c: New test.
* gcc.target/or1k/swap-2.c: New test.
---
gcc/config/or1k/or1k.md | 6 +-
gcc/config/or1k/predicates.md | 18 ++++++
gcc/testsuite/gcc.target/or1k/swap-1.c | 86 ++++++++++++++++++++++++++
gcc/testsuite/gcc.target/or1k/swap-2.c | 63 +++++++++++++++++++
4 files changed, 170 insertions(+), 3 deletions(-)
create mode 100644 gcc/testsuite/gcc.target/or1k/swap-1.c
create mode 100644 gcc/testsuite/gcc.target/or1k/swap-2.c
diff --git a/gcc/config/or1k/or1k.md b/gcc/config/or1k/or1k.md
index 2dad51cd46b..757d899c442 100644
--- a/gcc/config/or1k/or1k.md
+++ b/gcc/config/or1k/or1k.md
@@ -328,11 +328,11 @@
;; Sign Extending
;; -------------------------------------------------------------------------
-;; Zero extension can always be done with AND and an extending load.
+;; Zero extension can always be done with AND or an extending load.
(define_insn "zero_extend<mode>si2"
[(set (match_operand:SI 0 "register_operand" "=r,r")
- (zero_extend:SI (match_operand:I12 1 "nonimmediate_operand" "r,m")))]
+ (zero_extend:SI (match_operand:I12 1 "reg_or_mem_operand" "r,m")))]
""
"@
l.andi\t%0, %1, <zext_andi>
@@ -344,7 +344,7 @@
(define_insn "extend<mode>si2"
[(set (match_operand:SI 0 "register_operand" "=r,r")
- (sign_extend:SI (match_operand:I12 1 "nonimmediate_operand" "r,m")))]
+ (sign_extend:SI (match_operand:I12 1 "reg_or_mem_operand" "r,m")))]
"TARGET_SEXT"
"@
l.ext<ldst>s\t%0, %1
diff --git a/gcc/config/or1k/predicates.md b/gcc/config/or1k/predicates.md
index 879236bca49..b895f1b4228 100644
--- a/gcc/config/or1k/predicates.md
+++ b/gcc/config/or1k/predicates.md
@@ -82,3 +82,21 @@
(define_predicate "equality_comparison_operator"
(match_code "ne,eq"))
+
+;; Borrowed from rs6000
+; Return true if the operand is in volatile memory. Note that during the
+;; RTL generation phase, memory_operand does not return TRUE for volatile
+;; memory references. So this function allows us to recognize volatile
+;; references where it's safe.
+(define_predicate "volatile_mem_operand"
+ (and (match_code "mem")
+ (match_test "MEM_VOLATILE_P (op)")
+ (if_then_else (match_test "reload_completed")
+ (match_operand 0 "memory_operand")
+ (match_test "memory_address_p (mode, XEXP (op, 0))"))))
+
+;; Return true if the operand is a register or memory; including volatile
+;; memory.
+(define_predicate "reg_or_mem_operand"
+ (ior (match_operand 0 "nonimmediate_operand")
+ (match_operand 0 "volatile_mem_operand")))
diff --git a/gcc/testsuite/gcc.target/or1k/swap-1.c
b/gcc/testsuite/gcc.target/or1k/swap-1.c
new file mode 100644
index 00000000000..233c4b71627
--- /dev/null
+++ b/gcc/testsuite/gcc.target/or1k/swap-1.c
@@ -0,0 +1,86 @@
+/* { dg-do run } */
+/* { dg-options "-Os -mhard-mul -msoft-div -msoft-float" } */
+
+/* Copyright (C) 2018-2019 Free Software Foundation, Inc.
+ Copyright 2019 Broadcom. Richard Selvaggi, 2019-March-27
+ The term "Broadcom" refers to Broadcom Inc. and/or its subsidiaries.
+
+ This program is free software; you can redistribute it and/or modify
+ it under the terms of the GNU General Public License, version 2, as
+ published by the Free Software Foundation (the "GPL").
+
+ This program is distributed in the hope that it will be useful, but
+ WITHOUT ANY WARRANTY; without even the implied warranty of
+ MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+ General Public License version 2 (GPLv2) for more details.
+
+ You should have received a copy of the GNU General Public License
+ version 2 (GPLv2) along with this source code. */
+
+/* Notes:
+
+ This test failed on or1k GCC 7.2.0, and passes on or1k GCC 5.3.0
+ as well as the or1k port released in GCC 9.1.
+
+ The main program is organized as a loop structure so gcc does not
+ optimize-away the calls to swap_1(). Compiling with -O2 is still smart
+ enough to optimize-away the calls, but using -Os does not.
+ The bad code is only generated when compiled with -Os.
+
+ When the bad code is generated all code is okay except for the very last
+ instruction (a 'l.addc' in the l.jr delay slot).
+ Up to that point in execution, r11 and r12 contain the correct (expected)
+ values, but the execution of the final "l.addc" corrupts r11.
+
+ This test is added to ensure this does not come back. */
+
+#include <stdint.h>
+
+volatile static uint8_t g_doswap = 1;
+
+uint64_t swap_1 (uint64_t u64) {
+ uint32_t u64_lo, u64_hi, u64_tmp;
+
+ u64_lo = u64 & 0xFFFFFFFF;
+ u64_hi = u64 >> 32;
+
+ if (g_doswap)
+ {
+ u64_tmp = u64_lo;
+ u64_lo = u64_hi;
+ u64_hi = u64_tmp;
+ }
+
+ u64 = u64_lo;
+ u64 += ((uint64_t) u64_hi << 32);
+
+ return u64;
+}
+
+int main () {
+ int ret;
+ int iter;
+ uint64_t aa[2]; // inputs to swap function
+ uint64_t ee[2]; // expected outputs of swap function
+ uint64_t rr[2]; // actual results of swap function
+
+ g_doswap = 1;
+
+ // populate inputs, and expected outputs:
+ aa[0] = 0x123456789abcdef0;
+ aa[1] = 0x0123456789abcdef;
+
+ ee[0] = 0x9ABCDEF012345678;
+ ee[1] = 0x89ABCDEF01234567;
+
+ ret = 0;
+ for (iter = 0; iter < 2; iter++)
+ {
+ rr[iter] = swap_1(aa[iter]);
+ // early-out if there's a mis-match:
+ if (ee[iter] != rr[iter])
+ ret = 1;
+ }
+
+ return ret;
+}
diff --git a/gcc/testsuite/gcc.target/or1k/swap-2.c
b/gcc/testsuite/gcc.target/or1k/swap-2.c
new file mode 100644
index 00000000000..8ddea4e659f
--- /dev/null
+++ b/gcc/testsuite/gcc.target/or1k/swap-2.c
@@ -0,0 +1,63 @@
+/* { dg-do compile } */
+/* { dg-options "-Os -mhard-mul -msoft-div -msoft-float" } */
+
+/* Copyright (C) 2018-2019 Free Software Foundation, Inc.
+ Copyright 2019 Broadcom. Richard Selvaggi, 2019-March-27
+ The term "Broadcom" refers to Broadcom Inc. and/or its subsidiaries.
+
+ This program is free software; you can redistribute it and/or modify
+ it under the terms of the GNU General Public License, version 2, as
+ published by the Free Software Foundation (the "GPL").
+
+ This program is distributed in the hope that it will be useful, but
+ WITHOUT ANY WARRANTY; without even the implied warranty of
+ MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+ General Public License version 2 (GPLv2) for more details.
+
+ You should have received a copy of the GNU General Public License
+ version 2 (GPLv2) along with this source code. */
+
+/* Notes:
+
+ This test failed on or1k GCC 7.2.0, and passes on or1k GCC 5.3.0
+ as well as the or1k port released in GCC 9.1.
+
+ The main program is organized as a loop structure so gcc does not
+ optimize-away the calls to swap_1(). Compiling with -O2 is still smart
+ enough to optimize-away the calls, but using -Os does not.
+ The bad code is only generated when compiled with -Os.
+
+ When the bad code is generated all code is okay except for the very last
+ instruction (a 'l.addc' in the l.jr delay slot).
+ Up to that point in execution, r11 and r12 contain the correct (expected)
+ values, but the execution of the final "l.addc" corrupts r11.
+
+ This test ensures an l.addc is not in the output. Also, while confirming
+ this test we uncovered PR/90363, we use it to check for that as well. */
+
+#include <stdint.h>
+
+volatile static uint8_t g_doswap = 1;
+
+uint64_t swap_1 (uint64_t u64) {
+ uint32_t u64_lo, u64_hi, u64_tmp;
+
+ u64_lo = u64 & 0xFFFFFFFF;
+ u64_hi = u64 >> 32;
+
+ if (g_doswap)
+ {
+ u64_tmp = u64_lo;
+ u64_lo = u64_hi;
+ u64_hi = u64_tmp;
+ }
+
+ u64 = u64_lo;
+ u64 += ((uint64_t) u64_hi << 32);
+
+ return u64;
+}
+
+/* Check to ensure the volitile load does not get zero extended. */
+/* { dg-final { scan-assembler-not "0xff" } } */
+/* { dg-final { scan-assembler-not "l.addc" } } */
--
2.19.1
