https://gcc.gnu.org/g:3d4d82211c8cbfde0b852bde1603b5d549426df7
commit r15-9036-g3d4d82211c8cbfde0b852bde1603b5d549426df7
Author: Maciej W. Rozycki <ma...@orcam.me.uk>
Date: Sun Mar 30 15:24:50 2025 +0100
Alpha: Add option to avoid data races for sub-longword memory stores
[PR117759]
With non-BWX Alpha implementations we have a problem of data races where
a 8-bit byte or 16-bit word quantity is to be written to memory in that
in those cases we use an unprotected RMW access of a 32-bit longword or
64-bit quadword width. If contents of the longword or quadword accessed
outside the byte or word to be written are changed midway through by a
concurrent write executing on the same CPU such as by a signal handler
or a parallel write executing on another CPU such as by another thread
or via a shared memory segment, then the concluding write of the RMW
access will clobber them. This is especially important for the safety
of RCU algorithms, but is otherwise an issue anyway.
To guard against these data races with byte and aligned word quantities
introduce the `-msafe-bwa' command-line option (standing for Safe Byte &
Word Access) that instructs the compiler to instead use an atomic RMW
access sequence where byte and word memory access machine instructions
are not available. There is no change to code produced for BWX targets.
It would be sufficient for the secondary reload handle to use a pair of
scratch registers, as requested by `reload_out<mode>', but it would end
with poor code produced as one of the scratches would be occupied by
data retrieved and the other one would have to be reloaded with repeated
calculations, all within the LL/SC sequence.
Therefore I chose to add a dedicated `reload_out<mode>_safe_bwa' handler
and ask for more scratches there by defining a 256-bit OI integer mode.
While reload is documented in our manual to support an arbitrary number
of scratches in reality it hasn't been implemented for IRA:
/* ??? It would be useful to be able to handle only two, or more than
three, operands, but for now we can only handle the case of having
exactly three: output, input and one temp/scratch. */
and it seems to be the case for LRA as well. Do what everyone else does
then and just have one wide multi-register scratch.
I note that the atomic sequences emitted are suboptimal performance-wise
as the looping branch for the unsuccessful completion of the sequence
points backwards, which means it will be predicted as taken despite that
in most cases it will fall through. I do not see it as a deficiency of
this change proposed as it takes care of recording that the branch is
unlikely to be taken, by calling `alpha_emit_unlikely_jump'. Therefore
generic code elsewhere should instead be investigated and adjusted
accordingly for the arrangement to actually take effect.
Add test cases accordingly.
There are notable regressions between a plain `-mno-bwx' configuration
and a `-mno-bwx -msafe-bwa' one:
FAIL: gcc.dg/torture/inline-mem-cpy-cmp-1.c -O0 execution test
FAIL: gcc.dg/torture/inline-mem-cpy-cmp-1.c -O1 execution test
FAIL: gcc.dg/torture/inline-mem-cpy-cmp-1.c -O2 execution test
FAIL: gcc.dg/torture/inline-mem-cpy-cmp-1.c -O3 -g execution test
FAIL: gcc.dg/torture/inline-mem-cpy-cmp-1.c -Os execution test
FAIL: gcc.dg/torture/inline-mem-cpy-cmp-1.c -O2 -flto
-fno-use-linker-plugin -flto-partition=none execution test
FAIL: gcc.dg/torture/inline-mem-cpy-cmp-1.c -O2 -flto -fuse-linker-plugin
-fno-fat-lto-objects execution test
FAIL: g++.dg/init/array25.C -std=c++17 execution test
FAIL: g++.dg/init/array25.C -std=c++98 execution test
FAIL: g++.dg/init/array25.C -std=c++26 execution test
They come from the fact that these test cases play tricks with alignment
and end up calling code that expects a reference to aligned data but is
handed one to unaligned data.
This doesn't cause a visible problem with plain `-mno-bwx' code, because
the resulting alignment exception is fixed up by Linux. There's no such
handling currently implemented for LDL_L or LDQ_L instructions (which
are first in the sequence) and consequently the offender is issued with
SIGBUS instead. Suitable handling will be added to Linux to complement
this change that will emulate the trapping instructions[1], so these
interim regressions are seen as harmless and expected.
References:
[1] "Alpha: Emulate unaligned LDx_L/STx_C for data consistency",
<https://lore.kernel.org/r/alpine.deb.2.21.2502181912230.65...@angie.orcam.me.uk/>
gcc/
PR target/117759
* config/alpha/alpha-modes.def (OI): New integer mode.
* config/alpha/alpha-protos.h (alpha_expand_mov_safe_bwa): New
prototype.
* config/alpha/alpha.cc (alpha_expand_mov_safe_bwa): New
function.
(alpha_secondary_reload): Handle TARGET_SAFE_BWA.
* config/alpha/alpha.md (aligned_store_safe_bwa)
(unaligned_store<mode>_safe_bwa, reload_out<mode>_safe_bwa)
(reload_out<mode>_unaligned_safe_bwa): New expanders.
(mov<mode>, movcqi, reload_out<mode>_aligned): Handle
TARGET_SAFE_BWA.
(reload_out<mode>): Guard against TARGET_SAFE_BWA.
* config/alpha/alpha.opt (msafe-bwa): New option.
* config/alpha/alpha.opt.urls: Regenerate.
* doc/invoke.texi (Option Summary, DEC Alpha Options): Document
the new option.
gcc/testsuite/
PR target/117759
* gcc.target/alpha/stb.c: New file.
* gcc.target/alpha/stb-bwa.c: New file.
* gcc.target/alpha/stb-bwx.c: New file.
* gcc.target/alpha/stba.c: New file.
* gcc.target/alpha/stba-bwa.c: New file.
* gcc.target/alpha/stba-bwx.c: New file.
* gcc.target/alpha/stw.c: New file.
* gcc.target/alpha/stw-bwa.c: New file.
* gcc.target/alpha/stw-bwx.c: New file.
* gcc.target/alpha/stwa.c: New file.
* gcc.target/alpha/stwa-bwa.c: New file.
* gcc.target/alpha/stwa-bwx.c: New file.
Diff:
---
gcc/config/alpha/alpha-modes.def | 4 +
gcc/config/alpha/alpha-protos.h | 1 +
gcc/config/alpha/alpha.cc | 68 ++++++++++++-
gcc/config/alpha/alpha.md | 155 +++++++++++++++++++++++++++++-
gcc/config/alpha/alpha.opt | 4 +
gcc/config/alpha/alpha.opt.urls | 3 +
gcc/doc/invoke.texi | 9 ++
gcc/testsuite/gcc.target/alpha/stb-bwa.c | 28 ++++++
gcc/testsuite/gcc.target/alpha/stb-bwx.c | 16 +++
gcc/testsuite/gcc.target/alpha/stb.c | 25 +++++
gcc/testsuite/gcc.target/alpha/stba-bwa.c | 35 +++++++
gcc/testsuite/gcc.target/alpha/stba-bwx.c | 23 +++++
gcc/testsuite/gcc.target/alpha/stba.c | 33 +++++++
gcc/testsuite/gcc.target/alpha/stw-bwa.c | 28 ++++++
gcc/testsuite/gcc.target/alpha/stw-bwx.c | 16 +++
gcc/testsuite/gcc.target/alpha/stw.c | 25 +++++
gcc/testsuite/gcc.target/alpha/stwa-bwa.c | 35 +++++++
gcc/testsuite/gcc.target/alpha/stwa-bwx.c | 23 +++++
gcc/testsuite/gcc.target/alpha/stwa.c | 33 +++++++
19 files changed, 558 insertions(+), 6 deletions(-)
diff --git a/gcc/config/alpha/alpha-modes.def b/gcc/config/alpha/alpha-modes.def
index d2441efc0033..9392979cccc9 100644
--- a/gcc/config/alpha/alpha-modes.def
+++ b/gcc/config/alpha/alpha-modes.def
@@ -17,6 +17,10 @@ You should have received a copy of the GNU General Public
License
along with GCC; see the file COPYING3. If not see
<http://www.gnu.org/licenses/>. */
+/* 256-bit integer mode used by "reload_out<mode>_safe_bwa" secondary
+ reload patterns to obtain 4 scratch registers. */
+INT_MODE (OI, 32);
+
/* 128-bit floating point. This gets reset in alpha_option_override
if VAX float format is in use. */
FLOAT_MODE (TF, 16, ieee_quad_format);
diff --git a/gcc/config/alpha/alpha-protos.h b/gcc/config/alpha/alpha-protos.h
index 6d28fa88ecf9..3efdfe5a4ab2 100644
--- a/gcc/config/alpha/alpha-protos.h
+++ b/gcc/config/alpha/alpha-protos.h
@@ -43,6 +43,7 @@ extern enum reg_class alpha_preferred_reload_class (rtx, enum
reg_class);
extern void alpha_set_memflags (rtx, rtx);
extern bool alpha_split_const_mov (machine_mode, rtx *);
extern bool alpha_expand_mov (machine_mode, rtx *);
+extern bool alpha_expand_mov_safe_bwa (machine_mode, rtx *);
extern bool alpha_expand_mov_nobwx (machine_mode, rtx *);
extern void alpha_expand_movmisalign (machine_mode, rtx *);
extern void alpha_emit_floatuns (rtx[]);
diff --git a/gcc/config/alpha/alpha.cc b/gcc/config/alpha/alpha.cc
index d3e8a3a9756e..72a985985967 100644
--- a/gcc/config/alpha/alpha.cc
+++ b/gcc/config/alpha/alpha.cc
@@ -1661,8 +1661,10 @@ alpha_secondary_reload (bool in_p, rtx x, reg_class_t
rclass_i,
if (!aligned_memory_operand (x, mode))
sri->icode = direct_optab_handler (reload_in_optab, mode);
}
- else
+ else if (aligned_memory_operand (x, mode) || !TARGET_SAFE_BWA)
sri->icode = direct_optab_handler (reload_out_optab, mode);
+ else
+ sri->icode = code_for_reload_out_safe_bwa (mode);
return NO_REGS;
}
}
@@ -2391,6 +2393,70 @@ alpha_expand_mov_nobwx (machine_mode mode, rtx *operands)
return false;
}
+/* Expand a multi-thread and async-signal safe QImode or HImode
+ move instruction; return true if all work is done. */
+
+bool
+alpha_expand_mov_safe_bwa (machine_mode mode, rtx *operands)
+{
+ /* If the output is not a register, the input must be. */
+ if (MEM_P (operands[0]))
+ operands[1] = force_reg (mode, operands[1]);
+
+ /* If it's a memory load, the sequence is the usual non-BWX one. */
+ if (any_memory_operand (operands[1], mode))
+ return alpha_expand_mov_nobwx (mode, operands);
+
+ /* Handle memory store cases, unaligned and aligned. The only case
+ where we can be called during reload is for aligned loads; all
+ other cases require temporaries. */
+ if (any_memory_operand (operands[0], mode))
+ {
+ if (aligned_memory_operand (operands[0], mode))
+ {
+ rtx label = gen_rtx_LABEL_REF (DImode, gen_label_rtx ());
+ emit_label (XEXP (label, 0));
+
+ rtx aligned_mem, bitnum;
+ rtx status = gen_reg_rtx (SImode);
+ rtx temp = gen_reg_rtx (SImode);
+ get_aligned_mem (operands[0], &aligned_mem, &bitnum);
+ emit_insn (gen_aligned_store_safe_bwa (aligned_mem, operands[1],
+ bitnum, status, temp));
+
+ rtx cond = gen_rtx_EQ (DImode,
+ gen_rtx_SUBREG (DImode, status, 0),
+ const0_rtx);
+ alpha_emit_unlikely_jump (cond, label);
+ }
+ else
+ {
+ rtx addr = gen_reg_rtx (DImode);
+ emit_insn (gen_rtx_SET (addr, get_unaligned_address (operands[0])));
+
+ rtx aligned_addr = gen_reg_rtx (DImode);
+ emit_insn (gen_rtx_SET (aligned_addr,
+ gen_rtx_AND (DImode, addr, GEN_INT (-8))));
+
+ rtx label = gen_rtx_LABEL_REF (DImode, gen_label_rtx ());
+ emit_label (XEXP (label, 0));
+
+ rtx status = gen_reg_rtx (DImode);
+ rtx temp = gen_reg_rtx (DImode);
+ rtx seq = gen_unaligned_store_safe_bwa (mode, addr, operands[1],
+ aligned_addr, status, temp);
+ alpha_set_memflags (seq, operands[0]);
+ emit_insn (seq);
+
+ rtx cond = gen_rtx_EQ (DImode, status, const0_rtx);
+ alpha_emit_unlikely_jump (cond, label);
+ }
+ return true;
+ }
+
+ return false;
+}
+
/* Implement the movmisalign patterns. One of the operands is a memory
that is not naturally aligned. Emit instructions to load it. */
diff --git a/gcc/config/alpha/alpha.md b/gcc/config/alpha/alpha.md
index 178ce992206d..3b0df611fa7a 100644
--- a/gcc/config/alpha/alpha.md
+++ b/gcc/config/alpha/alpha.md
@@ -4200,6 +4200,31 @@
<< INTVAL (operands[2])));
})
+;; Multi-thread and async-signal safe variant. Operand 0 is the aligned
+;; SImode MEM. Operand 1 is the data to store. Operand 2 is the number
+;; of bits within the word that the value should be placed. Operand 3 is
+;; the SImode status. Operand 4 is a SImode temporary.
+
+(define_expand "aligned_store_safe_bwa"
+ [(set (match_operand:SI 3 "register_operand")
+ (unspec_volatile:SI
+ [(match_operand:SI 0 "memory_operand")] UNSPECV_LL))
+ (set (subreg:DI (match_dup 3) 0)
+ (and:DI (subreg:DI (match_dup 3) 0) (match_dup 5)))
+ (set (subreg:DI (match_operand:SI 4 "register_operand") 0)
+ (ashift:DI (zero_extend:DI (match_operand 1 "register_operand"))
+ (match_operand:DI 2 "const_int_operand")))
+ (set (subreg:DI (match_dup 3) 0)
+ (ior:DI (subreg:DI (match_dup 4) 0) (subreg:DI (match_dup 3) 0)))
+ (parallel [(set (subreg:DI (match_dup 3) 0)
+ (unspec_volatile:DI [(const_int 0)] UNSPECV_SC))
+ (set (match_dup 0) (match_dup 3))])]
+ ""
+{
+ operands[5] = GEN_INT (~(GET_MODE_MASK (GET_MODE (operands[1]))
+ << INTVAL (operands[2])));
+})
+
;; For the unaligned byte and halfword cases, we use code similar to that
;; in the Architecture book, but reordered to lower the number of registers
;; required. Operand 0 is the address. Operand 1 is the data to store.
@@ -4227,6 +4252,31 @@
""
"operands[5] = GEN_INT (GET_MODE_MASK (<MODE>mode));")
+;; Multi-thread and async-signal safe variant. Operand 0 is the address.
+;; Operand 1 is the data to store. Operand 2 is the aligned address.
+;; Operand 3 is the DImode status. Operand 4 is a DImode temporary.
+
+(define_expand "@unaligned_store<mode>_safe_bwa"
+ [(set (match_operand:DI 3 "register_operand")
+ (unspec_volatile:DI
+ [(mem:DI (match_operand:DI 2 "register_operand"))] UNSPECV_LL))
+ (set (match_dup 3)
+ (and:DI (not:DI
+ (ashift:DI (match_dup 5)
+ (ashift:DI (match_operand:DI 0 "register_operand")
+ (const_int 3))))
+ (match_dup 3)))
+ (set (match_operand:DI 4 "register_operand")
+ (ashift:DI (zero_extend:DI
+ (match_operand:I12MODE 1 "register_operand"))
+ (ashift:DI (match_dup 0) (const_int 3))))
+ (set (match_dup 3) (ior:DI (match_dup 4) (match_dup 3)))
+ (parallel [(set (match_dup 3)
+ (unspec_volatile:DI [(const_int 0)] UNSPECV_SC))
+ (set (mem:DI (match_dup 2)) (match_dup 3))])]
+ ""
+ "operands[5] = GEN_INT (GET_MODE_MASK (<MODE>mode));")
+
;; Here are the define_expand's for QI and HI moves that use the above
;; patterns. We have the normal sets, plus the ones that need scratch
;; registers for reload.
@@ -4236,8 +4286,8 @@
(match_operand:I12MODE 1 "general_operand"))]
""
{
- if (TARGET_BWX
- ? alpha_expand_mov (<MODE>mode, operands)
+ if (TARGET_BWX ? alpha_expand_mov (<MODE>mode, operands)
+ : TARGET_SAFE_BWA ? alpha_expand_mov_safe_bwa (<MODE>mode, operands)
: alpha_expand_mov_nobwx (<MODE>mode, operands))
DONE;
})
@@ -4292,7 +4342,9 @@
operands[1] = gen_lowpart (HImode, operands[1]);
do_aligned2:
operands[0] = gen_lowpart (HImode, operands[0]);
- done = alpha_expand_mov_nobwx (HImode, operands);
+ done = (TARGET_SAFE_BWA
+ ? alpha_expand_mov_safe_bwa (HImode, operands)
+ : alpha_expand_mov_nobwx (HImode, operands));
gcc_assert (done);
DONE;
}
@@ -4371,6 +4423,8 @@
}
else
{
+ gcc_assert (!TARGET_SAFE_BWA);
+
rtx addr = get_unaligned_address (operands[0]);
rtx scratch1 = gen_rtx_REG (DImode, regno);
rtx scratch2 = gen_rtx_REG (DImode, regno + 1);
@@ -4388,6 +4442,52 @@
DONE;
})
+(define_expand "@reload_out<mode>_safe_bwa"
+ [(parallel [(match_operand:RELOAD12 0 "any_memory_operand" "=m")
+ (match_operand:RELOAD12 1 "register_operand" "r")
+ (match_operand:OI 2 "register_operand" "=&r")])]
+ "!TARGET_BWX && TARGET_SAFE_BWA"
+{
+ unsigned regno = REGNO (operands[2]);
+
+ if (<MODE>mode == CQImode)
+ {
+ operands[0] = gen_lowpart (HImode, operands[0]);
+ operands[1] = gen_lowpart (HImode, operands[1]);
+ }
+
+ rtx addr = get_unaligned_address (operands[0]);
+ rtx status = gen_rtx_REG (DImode, regno);
+ rtx areg = gen_rtx_REG (DImode, regno + 1);
+ rtx aligned_addr = gen_rtx_REG (DImode, regno + 2);
+ rtx scratch = gen_rtx_REG (DImode, regno + 3);
+
+ if (REG_P (addr))
+ areg = addr;
+ else
+ emit_move_insn (areg, addr);
+ emit_move_insn (aligned_addr, gen_rtx_AND (DImode, areg, GEN_INT (-8)));
+
+ rtx label = gen_label_rtx ();
+ emit_label (label);
+ LABEL_NUSES (label) = 1;
+
+ rtx seq = gen_reload_out<reloadmode>_unaligned_safe_bwa (areg, operands[1],
+ aligned_addr,
+ status, scratch);
+ alpha_set_memflags (seq, operands[0]);
+ emit_insn (seq);
+
+ rtx label_ref = gen_rtx_LABEL_REF (DImode, label);
+ rtx cond = gen_rtx_EQ (DImode, status, const0_rtx);
+ rtx jump = alpha_emit_unlikely_jump (cond, label_ref);
+ JUMP_LABEL (jump) = label;
+
+ cfun->split_basic_blocks_after_reload = 1;
+
+ DONE;
+})
+
;; Helpers for the above. The way reload is structured, we can't
;; always get a proper address for a stack slot during reload_foo
;; expansion, so we must delay our address manipulations until after.
@@ -4420,10 +4520,55 @@
{
rtx aligned_mem, bitnum;
get_aligned_mem (operands[0], &aligned_mem, &bitnum);
- emit_insn (gen_aligned_store (aligned_mem, operands[1], bitnum,
- operands[2], operands[3]));
+ if (TARGET_SAFE_BWA)
+ {
+ rtx label = gen_label_rtx ();
+ emit_label (label);
+ LABEL_NUSES (label) = 1;
+
+ rtx status = operands[2];
+ rtx temp = operands[3];
+ emit_insn (gen_aligned_store_safe_bwa (aligned_mem, operands[1], bitnum,
+ status, temp));
+
+ rtx label_ref = gen_rtx_LABEL_REF (DImode, label);
+ rtx cond = gen_rtx_EQ (DImode, gen_rtx_SUBREG (DImode, status, 0),
+ const0_rtx);
+ rtx jump = alpha_emit_unlikely_jump (cond, label_ref);
+ JUMP_LABEL (jump) = label;
+
+ cfun->split_basic_blocks_after_reload = 1;
+ }
+ else
+ emit_insn (gen_aligned_store (aligned_mem, operands[1], bitnum,
+ operands[2], operands[3]));
DONE;
})
+
+;; Operand 0 is the address. Operand 1 is the data to store. Operand 2
+;; is the aligned address. Operand 3 is the DImode status. Operand 4 is
+;; a DImode scratch.
+
+(define_expand "reload_out<mode>_unaligned_safe_bwa"
+ [(set (match_operand:DI 3 "register_operand")
+ (unspec_volatile:DI [(mem:DI (match_operand:DI 2 "register_operand"))]
+ UNSPECV_LL))
+ (set (match_dup 3)
+ (and:DI (not:DI
+ (ashift:DI (match_dup 5)
+ (ashift:DI (match_operand:DI 0 "register_operand")
+ (const_int 3))))
+ (match_dup 3)))
+ (set (match_operand:DI 4 "register_operand")
+ (ashift:DI (zero_extend:DI
+ (match_operand:I12MODE 1 "register_operand"))
+ (ashift:DI (match_dup 0) (const_int 3))))
+ (set (match_dup 3) (ior:DI (match_dup 4) (match_dup 3)))
+ (parallel [(set (match_dup 3)
+ (unspec_volatile:DI [(const_int 0)] UNSPECV_SC))
+ (set (mem:DI (match_dup 2)) (match_dup 3))])]
+ ""
+ "operands[5] = GEN_INT (GET_MODE_MASK (<MODE>mode));")
;; Vector operations
diff --git a/gcc/config/alpha/alpha.opt b/gcc/config/alpha/alpha.opt
index f5ecc7b41a74..1081a6c5f3bc 100644
--- a/gcc/config/alpha/alpha.opt
+++ b/gcc/config/alpha/alpha.opt
@@ -69,6 +69,10 @@ mcix
Target Mask(CIX)
Emit code for the counting ISA extension.
+msafe-bwa
+Target Mask(SAFE_BWA)
+Emit multi-thread and async-signal safe code for byte and word memory accesses.
+
mexplicit-relocs
Target Mask(EXPLICIT_RELOCS)
Emit code using explicit relocation directives.
diff --git a/gcc/config/alpha/alpha.opt.urls b/gcc/config/alpha/alpha.opt.urls
index a55c08328c37..e877e36bd2b9 100644
--- a/gcc/config/alpha/alpha.opt.urls
+++ b/gcc/config/alpha/alpha.opt.urls
@@ -35,6 +35,9 @@ UrlSuffix(gcc/DEC-Alpha-Options.html#index-mfix)
mcix
UrlSuffix(gcc/DEC-Alpha-Options.html#index-mcix)
+msafe-bwa
+UrlSuffix(gcc/DEC-Alpha-Options.html#index-msafe-bwa)
+
mexplicit-relocs
UrlSuffix(gcc/DEC-Alpha-Options.html#index-mexplicit-relocs)
diff --git a/gcc/doc/invoke.texi b/gcc/doc/invoke.texi
index df4610908243..36d81b0c6bc6 100644
--- a/gcc/doc/invoke.texi
+++ b/gcc/doc/invoke.texi
@@ -991,6 +991,7 @@ Objective-C and Objective-C++ Dialects}.
-mtrap-precision=@var{mode} -mbuild-constants
-mcpu=@var{cpu-type} -mtune=@var{cpu-type}
-mbwx -mmax -mfix -mcix
+-msafe-bwa
-mfloat-vax -mfloat-ieee
-mexplicit-relocs -msmall-data -mlarge-data
-msmall-text -mlarge-text
@@ -26302,6 +26303,14 @@ CIX, FIX and MAX instruction sets. The default is to
use the instruction
sets supported by the CPU type specified via @option{-mcpu=} option or that
of the CPU on which GCC was built if none is specified.
+@opindex msafe-bwa
+@opindex mno-safe-bwa
+@item -msafe-bwa
+@itemx -mno-safe-bwa
+Indicate whether in the absence of the optional BWX instruction set
+GCC should generate multi-thread and async-signal safe code for byte
+and aligned word memory accesses.
+
@opindex mfloat-vax
@opindex mfloat-ieee
@item -mfloat-vax
diff --git a/gcc/testsuite/gcc.target/alpha/stb-bwa.c
b/gcc/testsuite/gcc.target/alpha/stb-bwa.c
new file mode 100644
index 000000000000..d7a45dbb9cae
--- /dev/null
+++ b/gcc/testsuite/gcc.target/alpha/stb-bwa.c
@@ -0,0 +1,28 @@
+/* { dg-do compile } */
+/* { dg-options "-mno-bwx -msafe-bwa" } */
+/* { dg-skip-if "" { *-*-* } { "-O0" } } */
+
+void
+stb (char *p, char v)
+{
+ *p = v;
+}
+
+/* Expect assembly such as:
+
+ bic $16,7,$2
+ insbl $17,$16,$17
+$L2:
+ ldq_l $1,0($2)
+ mskbl $1,$16,$1
+ bis $17,$1,$1
+ stq_c $1,0($2)
+ beq $1,$L2
+
+ with address masking. */
+
+/* { dg-final { scan-assembler-times "\\sldq_l\\s" 1 } } */
+/* { dg-final { scan-assembler-times "\\sstq_c\\s" 1 } } */
+/* { dg-final { scan-assembler-times "\\sinsbl\\s" 1 } } */
+/* { dg-final { scan-assembler-times "\\smskbl\\s" 1 } } */
+/* { dg-final { scan-assembler-times "\\sbic\\s\\\$\[0-9\]+,7,\\\$\[0-9\]+\\s"
1 } } */
diff --git a/gcc/testsuite/gcc.target/alpha/stb-bwx.c
b/gcc/testsuite/gcc.target/alpha/stb-bwx.c
new file mode 100644
index 000000000000..556397b9e715
--- /dev/null
+++ b/gcc/testsuite/gcc.target/alpha/stb-bwx.c
@@ -0,0 +1,16 @@
+/* { dg-do compile } */
+/* { dg-options "-mbwx" } */
+/* { dg-skip-if "" { *-*-* } { "-O0" } } */
+
+void
+stb (char *p, char v)
+{
+ *p = v;
+}
+
+/* Expect assembly such as:
+
+ stb $17,0($16)
+ */
+
+/* { dg-final { scan-assembler-times "\\sstb\\s\\\$17,0\\\(\\\$16\\\)\\s" 1 }
} */
diff --git a/gcc/testsuite/gcc.target/alpha/stb.c
b/gcc/testsuite/gcc.target/alpha/stb.c
new file mode 100644
index 000000000000..4953bc4dcef0
--- /dev/null
+++ b/gcc/testsuite/gcc.target/alpha/stb.c
@@ -0,0 +1,25 @@
+/* { dg-do compile } */
+/* { dg-options "-mno-bwx -mno-safe-bwa" } */
+/* { dg-skip-if "" { *-*-* } { "-O0" } } */
+
+void
+stb (char *p, char v)
+{
+ *p = v;
+}
+
+/* Expect assembly such as:
+
+ insbl $17,$16,$17
+ ldq_u $1,0($16)
+ mskbl $1,$16,$1
+ bis $17,$1,$17
+ stq_u $17,0($16)
+
+ without address masking. */
+
+/* { dg-final { scan-assembler-times "\\sldq_u\\s" 1 } } */
+/* { dg-final { scan-assembler-times "\\sstq_u\\s" 1 } } */
+/* { dg-final { scan-assembler-times "\\sinsbl\\s" 1 } } */
+/* { dg-final { scan-assembler-times "\\smskbl\\s" 1 } } */
+/* { dg-final { scan-assembler-not "\\sbic\\s\\\$\[0-9\]+,7,\\\$\[0-9\]+\\s" }
} */
diff --git a/gcc/testsuite/gcc.target/alpha/stba-bwa.c
b/gcc/testsuite/gcc.target/alpha/stba-bwa.c
new file mode 100644
index 000000000000..07cf9542669b
--- /dev/null
+++ b/gcc/testsuite/gcc.target/alpha/stba-bwa.c
@@ -0,0 +1,35 @@
+/* { dg-do compile } */
+/* { dg-options "-mno-bwx -msafe-bwa" } */
+/* { dg-skip-if "" { *-*-* } { "-O0" } } */
+
+typedef union
+ {
+ int i;
+ char c;
+ }
+char_a;
+
+void
+stba (char_a *p, char v)
+{
+ p->c = v;
+}
+
+/* Expect assembly such as:
+
+ and $17,0xff,$17
+$L2:
+ ldl_l $1,0($16)
+ bic $1,255,$1
+ bis $17,$1,$1
+ stl_c $1,0($16)
+ beq $1,$L2
+
+ without any INSBL or MSKBL instructions and without address masking. */
+
+/* { dg-final { scan-assembler-times "\\sldl_l\\s" 1 } } */
+/* { dg-final { scan-assembler-times "\\sstl_c\\s" 1 } } */
+/* { dg-final { scan-assembler-times
"\\sand\\s\\\$\[0-9\]+,0xff,\\\$\[0-9\]+\\s" 1 } } */
+/* { dg-final { scan-assembler-times
"\\sbic\\s\\\$\[0-9\]+,255,\\\$\[0-9\]+\\s" 1 } } */
+/* { dg-final { scan-assembler-not "\\sbic\\s\\\$\[0-9\]+,7,\\\$\[0-9\]+\\s" }
} */
+/* { dg-final { scan-assembler-not "\\s(?:insbl|mskbl)\\s" } } */
diff --git a/gcc/testsuite/gcc.target/alpha/stba-bwx.c
b/gcc/testsuite/gcc.target/alpha/stba-bwx.c
new file mode 100644
index 000000000000..08b51b1985fc
--- /dev/null
+++ b/gcc/testsuite/gcc.target/alpha/stba-bwx.c
@@ -0,0 +1,23 @@
+/* { dg-do compile } */
+/* { dg-options "-mbwx" } */
+/* { dg-skip-if "" { *-*-* } { "-O0" } } */
+
+typedef union
+ {
+ int i;
+ char c;
+ }
+char_a;
+
+void
+stba (char_a *p, char v)
+{
+ p->c = v;
+}
+
+/* Expect assembly such as:
+
+ stb $17,0($16)
+ */
+
+/* { dg-final { scan-assembler-times "\\sstb\\s\\\$17,0\\\(\\\$16\\\)\\s" 1 }
} */
diff --git a/gcc/testsuite/gcc.target/alpha/stba.c
b/gcc/testsuite/gcc.target/alpha/stba.c
new file mode 100644
index 000000000000..fe7856ca3ce5
--- /dev/null
+++ b/gcc/testsuite/gcc.target/alpha/stba.c
@@ -0,0 +1,33 @@
+/* { dg-do compile } */
+/* { dg-options "-mno-bwx -mno-safe-bwa" } */
+/* { dg-skip-if "" { *-*-* } { "-O0" } } */
+
+typedef union
+ {
+ int i;
+ char c;
+ }
+char_a;
+
+void
+stba (char_a *p, char v)
+{
+ p->c = v;
+}
+
+/* Expect assembly such as:
+
+ and $17,0xff,$17
+ ldl $1,0($16)
+ bic $1,255,$1
+ bis $17,$1,$17
+ stl $17,0($16)
+
+ without any INSBL or MSKBL instructions and without address masking. */
+
+/* { dg-final { scan-assembler-times "\\sldl\\s" 1 } } */
+/* { dg-final { scan-assembler-times "\\sstl\\s" 1 } } */
+/* { dg-final { scan-assembler-times
"\\sand\\s\\\$\[0-9\]+,0xff,\\\$\[0-9\]+\\s" 1 } } */
+/* { dg-final { scan-assembler-times
"\\sbic\\s\\\$\[0-9\]+,255,\\\$\[0-9\]+\\s" 1 } } */
+/* { dg-final { scan-assembler-not "\\sbic\\s\\\$\[0-9\]+,7,\\\$\[0-9\]+\\s" }
} */
+/* { dg-final { scan-assembler-not "\\s(?:insbl|mskbl)\\s" } } */
diff --git a/gcc/testsuite/gcc.target/alpha/stw-bwa.c
b/gcc/testsuite/gcc.target/alpha/stw-bwa.c
new file mode 100644
index 000000000000..8b764b3dbbfd
--- /dev/null
+++ b/gcc/testsuite/gcc.target/alpha/stw-bwa.c
@@ -0,0 +1,28 @@
+/* { dg-do compile } */
+/* { dg-options "-mno-bwx -msafe-bwa" } */
+/* { dg-skip-if "" { *-*-* } { "-O0" } } */
+
+void
+stw (short *p, short v)
+{
+ *p = v;
+}
+
+/* Expect assembly such as:
+
+ bic $16,7,$2
+ inswl $17,$16,$17
+$L2:
+ ldq_l $1,0($2)
+ mskwl $1,$16,$1
+ bis $17,$1,$1
+ stq_c $1,0($2)
+ beq $1,$L2
+
+ with address masking. */
+
+/* { dg-final { scan-assembler-times "\\sldq_l\\s" 1 } } */
+/* { dg-final { scan-assembler-times "\\sstq_c\\s" 1 } } */
+/* { dg-final { scan-assembler-times "\\sinswl\\s" 1 } } */
+/* { dg-final { scan-assembler-times "\\smskwl\\s" 1 } } */
+/* { dg-final { scan-assembler-times "\\sbic\\s\\\$\[0-9\]+,7,\\\$\[0-9\]+\\s"
1 } } */
diff --git a/gcc/testsuite/gcc.target/alpha/stw-bwx.c
b/gcc/testsuite/gcc.target/alpha/stw-bwx.c
new file mode 100644
index 000000000000..b4f18add2f25
--- /dev/null
+++ b/gcc/testsuite/gcc.target/alpha/stw-bwx.c
@@ -0,0 +1,16 @@
+/* { dg-do compile } */
+/* { dg-options "-mbwx" } */
+/* { dg-skip-if "" { *-*-* } { "-O0" } } */
+
+void
+stw (short *p, short v)
+{
+ *p = v;
+}
+
+/* Expect assembly such as:
+
+ stw $17,0($16)
+ */
+
+/* { dg-final { scan-assembler-times "\\sstw\\s\\\$17,0\\\(\\\$16\\\)\\s" 1 }
} */
diff --git a/gcc/testsuite/gcc.target/alpha/stw.c
b/gcc/testsuite/gcc.target/alpha/stw.c
new file mode 100644
index 000000000000..655fdd91f80c
--- /dev/null
+++ b/gcc/testsuite/gcc.target/alpha/stw.c
@@ -0,0 +1,25 @@
+/* { dg-do compile } */
+/* { dg-options "-mno-bwx -mno-safe-bwa" } */
+/* { dg-skip-if "" { *-*-* } { "-O0" } } */
+
+void
+stw (short *p, short v)
+{
+ *p = v;
+}
+
+/* Expect assembly such as:
+
+ inswl $17,$16,$17
+ ldq_u $1,0($16)
+ mskwl $1,$16,$1
+ bis $17,$1,$17
+ stq_u $17,0($16)
+
+ without address masking. */
+
+/* { dg-final { scan-assembler-times "\\sldq_u\\s" 1 } } */
+/* { dg-final { scan-assembler-times "\\sstq_u\\s" 1 } } */
+/* { dg-final { scan-assembler-times "\\sinswl\\s" 1 } } */
+/* { dg-final { scan-assembler-times "\\smskwl\\s" 1 } } */
+/* { dg-final { scan-assembler-not "\\sbic\\s\\\$\[0-9\]+,7,\\\$\[0-9\]+\\s" }
} */
diff --git a/gcc/testsuite/gcc.target/alpha/stwa-bwa.c
b/gcc/testsuite/gcc.target/alpha/stwa-bwa.c
new file mode 100644
index 000000000000..9ee226e279bd
--- /dev/null
+++ b/gcc/testsuite/gcc.target/alpha/stwa-bwa.c
@@ -0,0 +1,35 @@
+/* { dg-do compile } */
+/* { dg-options "-mno-bwx -msafe-bwa" } */
+/* { dg-skip-if "" { *-*-* } { "-O0" } } */
+
+typedef union
+ {
+ int i;
+ short c;
+ }
+short_a;
+
+void
+stwa (short_a *p, short v)
+{
+ p->c = v;
+}
+
+/* Expect assembly such as:
+
+ zapnot $17,3,$17
+$L2:
+ ldl_l $1,0($16)
+ zapnot $1,252,$1
+ bis $17,$1,$1
+ stl_c $1,0($16)
+ beq $1,$L2
+
+ without any INSWL or MSKWL instructions and without address masking. */
+
+/* { dg-final { scan-assembler-times "\\sldl_l\\s" 1 } } */
+/* { dg-final { scan-assembler-times "\\sstl_c\\s" 1 } } */
+/* { dg-final { scan-assembler-times
"\\szapnot\\s\\\$\[0-9\]+,3,\\\$\[0-9\]+\\s" 1 } } */
+/* { dg-final { scan-assembler-times
"\\szapnot\\s\\\$\[0-9\]+,252,\\\$\[0-9\]+\\s" 1 } } */
+/* { dg-final { scan-assembler-not "\\sbic\\s\\\$\[0-9\]+,7,\\\$\[0-9\]+\\s" }
} */
+/* { dg-final { scan-assembler-not "\\s(?:inswl|mskwl)\\s" } } */
diff --git a/gcc/testsuite/gcc.target/alpha/stwa-bwx.c
b/gcc/testsuite/gcc.target/alpha/stwa-bwx.c
new file mode 100644
index 000000000000..6331d62986e6
--- /dev/null
+++ b/gcc/testsuite/gcc.target/alpha/stwa-bwx.c
@@ -0,0 +1,23 @@
+/* { dg-do compile } */
+/* { dg-options "-mbwx" } */
+/* { dg-skip-if "" { *-*-* } { "-O0" } } */
+
+typedef union
+ {
+ int i;
+ short c;
+ }
+short_a;
+
+void
+stwa (short_a *p, short v)
+{
+ p->c = v;
+}
+
+/* Expect assembly such as:
+
+ stw $17,0($16)
+ */
+
+/* { dg-final { scan-assembler-times "\\sstw\\s\\\$17,0\\\(\\\$16\\\)\\s" 1 }
} */
diff --git a/gcc/testsuite/gcc.target/alpha/stwa.c
b/gcc/testsuite/gcc.target/alpha/stwa.c
new file mode 100644
index 000000000000..6b273cf349a4
--- /dev/null
+++ b/gcc/testsuite/gcc.target/alpha/stwa.c
@@ -0,0 +1,33 @@
+/* { dg-do compile } */
+/* { dg-options "-mno-bwx -mno-safe-bwa" } */
+/* { dg-skip-if "" { *-*-* } { "-O0" } } */
+
+typedef union
+ {
+ int i;
+ short c;
+ }
+short_a;
+
+void
+stwa (short_a *p, short v)
+{
+ p->c = v;
+}
+
+/* Expect assembly such as:
+
+ zapnot $17,3,$17
+ ldl $1,0($16)
+ zapnot $1,252,$1
+ bis $17,$1,$17
+ stl $17,0($16)
+
+ without any INSWL or MSKWL instructions and without address masking. */
+
+/* { dg-final { scan-assembler-times "\\sldl\\s" 1 } } */
+/* { dg-final { scan-assembler-times "\\sstl\\s" 1 } } */
+/* { dg-final { scan-assembler-times
"\\szapnot\\s\\\$\[0-9\]+,3,\\\$\[0-9\]+\\s" 1 } } */
+/* { dg-final { scan-assembler-times
"\\szapnot\\s\\\$\[0-9\]+,252,\\\$\[0-9\]+\\s" 1 } } */
+/* { dg-final { scan-assembler-not "\\sbic\\s\\\$\[0-9\]+,7,\\\$\[0-9\]+\\s" }
} */
+/* { dg-final { scan-assembler-not "\\s(?:inswl|mskwl)\\s" } } */
