Commit graph

59 commits

Author SHA1 Message Date
Richard Henderson e751b45aea tcg/optimize: Improve find_better_copy
Prefer TEMP_CONST over anything else.

Backports 4c868ce6454872d395b29de8d82387b2ad14aeeb
2021-03-03 21:35:28 -05:00
Richard Henderson 8edc9b76dd tcg: Introduce TYPE_CONST temporaries
These will hold a single constant for the duration of the TB.
They are hashed, so that each value has one temp across the TB.

Not used yet, this is all infrastructure.

Backports c0522136adf550c7a0ef7c0755c1f9d1560d2757
2021-03-03 21:29:40 -05:00
Richard Henderson 6100deaffd tcg: Expand TempOptInfo to 64-bits
This propagates the extended value of TCGTemp.val that we did before.
In addition, it will be required for vector constants.

Backports 54795544e4cfb2fa198f7ca244b5ea9eaad322d4
2021-03-03 21:04:23 -05:00
Richard Henderson e84b88344a tcg: Rename struct tcg_temp_info to TempOptInfo
Fix this name vs our coding style.

Backports 6fcb98eda16b27d1999737346cdd4d3c1eae6a57
2021-03-03 20:52:59 -05:00
Richard Henderson 30739864d2 tcg: Consolidate 3 bits into enum TCGTempKind
The temp_fixed, temp_global, temp_local bits are all related.
Combine them into a single enumeration.

Backports ee17db83d2dce35792e9bf03366af193e5e0e5c9
2021-03-03 20:41:24 -05:00
Richard Henderson 9d453e820a tcg: Introduce INDEX_op_qemu_st8_i32
Enable this on i386 to restrict the set of input registers
for an 8-bit store, as required by the architecture. This
removes the last use of scratch registers for user-only mode.

Backports 07ce0b05300de5bc8f1932a4cfbe38f3323e5ab1
2021-03-03 19:51:20 -05:00
Thomas Huth 6a22a7b80e tcg/optimize: Add fallthrough annotations
To be able to compile this file with -Werror=implicit-fallthrough,
we need to add some fallthrough annotations to the case statements
that might fall through. Unfortunately, the typical "/* fallthrough */"
comments do not work here as expected since some case labels are
wrapped in macros and the compiler fails to match the comments in
this case. But using __attribute__((fallthrough)) seems to work fine,
so let's use that instead (by introducing a new QEMU_FALLTHROUGH
macro in our compiler.h header file).

Backports d84568b773fe1fc469c4d8419c3545be52eec82c
2021-03-03 19:18:50 -05:00
Richard Henderson 45af31fcb4 tcg/optimize: Fold dup2_vec
When the two arguments are identical, this can be reduced to
dup_vec or to mov_vec from a tcg_constant_vec.

Backports commit 1dc4fe70128db05237a00eda6eb15e2b44deb31f
2021-03-01 19:46:14 -05:00
Tony Nguyen f75368cd0f
tcg: TCGMemOp is now accelerator independent MemOp
Preparation for collapsing the two byte swaps, adjust_endianness and
handle_bswap, along the I/O path.

Target dependant attributes are conditionalized upon NEED_CPU_H.

Backports commit 14776ab5a12972ea439c7fb2203a4c15a09094b4 from qemu
2019-11-28 03:01:12 -05:00
Richard Henderson b2d75f4955
tcg: Fix constant folding of INDEX_op_extract2_i32
On a 64-bit host, discard any replications of the 32-bit
sign bit when performing the shift and merge.

Backports commit 80f4d7c3ae216c191fb403e149bcba88d6aa40bb from qemu
2019-08-08 19:25:01 -04:00
Richard Henderson 9a9b681b38
tcg: Do not recreate INDEX_op_neg_vec unless supported
Use tcg_can_emit_vec_op instead of just TCG_TARGET_HAS_neg_vec,
so that we check the type and vece for the actual operation.

Backports commit ac383dde33405106469d04a78de1d76f1a730cb1 from qemu
2019-05-16 14:28:41 -04:00
Richard Henderson 269fa0daba
tcg: Add INDEX_op_extract2_{i32,i64}
This will let backends implement the double-word shift operation.

Backports commit fce1296f135669eca85dc42154a2a352c818ad76 from qemu
2019-04-30 09:29:05 -04:00
Emilio G. Cota 0567c69235
tcg: Drop nargs from tcg_op_insert_{before,after}
It's unused since 75e8b9b7aa0b95a761b9add7e2f09248b101a392.

Backports commit ac1043f6d607aaac206c8aac42bc32f634f59395 from qemu
2018-12-18 06:00:13 -05:00
Richard Henderson fdb3d6488e
tcg/optimize: Optimize bswap
Somehow we forgot these operations, once upon a time.
This will allow immediate stores to have their bswap
optimized away.

Backports commit 6498594c8eda83c5f5915afc34bd03396f8de6df from qemu
2018-12-18 05:49:29 -05:00
Richard Henderson 9e8c8a617b
tcg/optimize: Do not skip default processing of dup_vec
If we do not opimize away dup_vec, we must mark its output as changed.

Backports commit 1fb57da72ae0886eba1234a2d98ddd10e88a9efc from qemu
2018-08-09 00:53:07 -04:00
Lioncash 99dbbf1571
tcg/optimize: Perform comparison pass with qemu
Keeps formatting and code synced
2018-03-12 18:06:29 -04:00
Richard Henderson 7f55d6ed69
tcg/optimize: Handle vector opcodes during optimize
Trivial move and constant propagation. Some identity and constant
function folding, but nothing that requires knowledge of the size
of the vector element.

Backports commit 170ba88f45bd7b1c5593021ed8e174f663b0bd1a from qemu
2018-03-06 16:10:09 -05:00
Richard Henderson 140058221d
tcg: Generalize TCGOp parameters
We had two fields specific to INDEX_op_call. Rename these and
add some macros so that the fields may be reused for other opcodes.

Backports commit cd9090aa9dbba30db8aec9a2fc103aaf1ab0f5a7 from qemu
2018-03-05 16:53:50 -05:00
Richard Henderson 7fe5f620df
tcg: Dynamically allocate TCGOps
With no fixed array allocation, we can't overflow a buffer.
This will be important as optimizations related to host vectors
may expand the number of ops used.

Use QTAILQ to link the ops together.

Backports commit 15fa08f8451babc88d733bd411d4c94976f9d0f8 from qemu
2018-03-05 16:34:40 -05:00
Richard Henderson ab9df6244c
tcg: Use offsets not indices for TCGv_*
Using the offset of a temporary, relative to TCGContext, rather than
its index means that we don't use 0. That leaves offset 0 free for
a NULL representation without having to leave index 0 unused.

Backports commit e89b28a63501c0ad6d2501fe851d0c5202055e70 from qemu
2018-03-05 10:12:08 -05:00
Richard Henderson 9f8c6a456b
tcg: Use per-temp state data in optimize
While we're touching many of the lines anyway, adjust the naming
of the functions to better distinguish when "TCGArg" vs "TCGTemp"
should be used.

Backports commit 6349039d0b06eda59820629b934944246b14a1c1 from qemu
2018-03-05 08:24:06 -05:00
Richard Henderson 010ded3088
tcg: Add temp_global bit to TCGTemp
This avoids needing to test the index of a temp against nb_globals.

Backports commit fa477d25470187030614288d35bc734edffa41ee from qemu
2018-03-05 07:21:10 -05:00
Richard Henderson a9c46ad7a0
tcg: Introduce arg_temp
Backports commit 434391390ba99996af1591b427a73b3f5c05065e from qemu
2018-03-05 07:17:44 -05:00
Richard Henderson 845cfc2ae9
tcg: Propagate args to op->args in optimizer
Backports commit acd937019bdaf933fcf1a7b57679ba07119c89b7 from qemu
2018-03-05 06:56:06 -05:00
Richard Henderson eb488f5bd6
tcg: Merge opcode arguments into TCGOp
Rather than have a separate buffer of 10*max_ops entries,
give each opcode 10 entries. The result is actually a bit
smaller and should have slightly more cache locality.

Backports commit 75e8b9b7aa0b95a761b9add7e2f09248b101a392 from qemu
2018-03-05 04:45:20 -05:00
Richard Henderson 5f6e7bbdbd
tcg: Add opcode for ctpop
The number of actual invocations of ctpop itself does not warrent
an opcode, but it is very helpful for POWER7 to use in generating
an expansion for ctz.

Backports commit a768e4e99247911f00c5c0267c12d4e207d5f6cc from qemu
2018-03-01 18:26:41 -05:00
Richard Henderson 2cf34e1b55
tcg: Add clz and ctz opcodes
Backports commit 0e28d0063bbd9e59a981ea2d20f82f30c5d956a8 from qemu
2018-03-01 16:04:11 -05:00
Richard Henderson 199b3859c4
tcg/optimize: Fold movcond 0/1 into setcond
Backports commit 333b21b809fc80ce67c8f6a7d1c7cc66437d9791 from qemu
2018-03-01 14:41:38 -05:00
Richard Henderson 8e0585dcb1
tcg: Add field extraction primitives
Adds tcg_gen_extract_* and tcg_gen_sextract_* for extraction of
fixed position bitfields, much like we already have for deposit.

Backports commit 7ec8bab3deae643b1ce579c2d65a244f30708330 from qemu
2018-03-01 13:21:30 -05:00
Alex Bennée bf72733576
tcg/optimize: move default return out of if statement
This is to appease sanitizer builds which complain that:

"error: control reaches end of non-void function"

Backports commit 550276ae0a88851edda2cb7fcdd64256dbb8e314 from qemu
2018-02-26 05:05:21 -05:00
Pranith Kumar 16d71f0f10
tcg: Optimize fence instructions
This commit optimizes fence instructions. Two optimizations are
currently implemented: (1) unnecessary duplicate fence instructions,
and (2) merging weaker fences into a stronger fence.

[rth: Merge tcg_optimize_mb back into tcg_optimize, so that we only
loop over the opcode stream once. Merge "unrelated" weaker barriers
into one stronger barrier.]

Backports commit 34f939218ce78163171addd63750e1e0300376ab from qemu
2018-02-26 03:29:59 -05:00
Richard Henderson ede1cae3dc
tcg: Lower indirect registers in a separate pass
Rather than rely on recursion during the middle of register allocation,
lower indirect registers to loads and stores off the indirect base into
plain temps.

For an x86_64 host, with sufficient registers, this results in identical
code, modulo the actual register assignments.

For an i686 host, with insufficient registers, this means that temps can
be (temporarily) spilled to the stack in order to satisfy an allocation.
This as opposed to the possibility of not being able to spill, to allocate
a register for the indirect base, in order to perform a spill.

Backports commit 5a18407f55ade924aa6397c9a043a9ffd59645fe from qemu
2018-02-25 22:32:28 -05:00
Richard Henderson 1547048a22
tcg: Reorg TCGOp chaining
Instead of using -1 as end of chain, use 0, and link through the 0
entry as a fully circular double-linked list.

Backports commit dcb8e75870e2de199db853697f8839cb603beefe from qemu
2018-02-25 21:44:50 -05:00
Paolo Bonzini 58693409ea
exec: extract exec/tb-context.h
TCG backends do not need most of exec-all.h; extract what they actually
need to a separate file or move it directly to tcg.h. The next patch
will stop including exec-all.h from everywhere.

Backports commit 00f6da6a1a5d1ce085334eccbb50ec899ceed513 from qemu
2018-02-24 02:09:58 -05:00
Paolo Bonzini 37f26922dd
qemu-common: push cpu.h inclusion out of qemu-common.h
Backports commit 33c11879fd422b759483ed25fef133ea900ea8d7 from qemu
2018-02-24 01:50:56 -05:00
Aurelien Jarno 355ed7cd08
tcg: use tcg_debug_assert instead of assert (fix performance regression)
The TCG code is quite performance sensitive, but at the same time can
also be quite tricky. That is why asserts that can be enabled with the
--enable-debug-tcg configure option.

This used to work the following way:

| #include "config.h"
|
| ...
|
| #if !defined(CONFIG_DEBUG_TCG) && !defined(NDEBUG)
| /* define it to suppress various consistency checks (faster) */
| #define NDEBUG
| #endif
|
| ...
|
| #include <assert.h>

Since commit 757e725b (tcg: Clean up includes) "config.h" as been
replaced by "qemu/osdep.h" which itself includes <assert.h>. As a
consequence the assertions are always enabled, even when using
--disable-debug-tcg, causing a performance regression, especially on
targets with many registers. For instance on qemu-system-ppc the
speed difference is about 15%.

tcg_debug_assert is controlled directly by CONFIG_DEBUG_TCG and already
uses in some places. This patch replaces all the calls to assert into
calss to tcg_debug_assert.

Backports commit eabb7b91b36b202b4dac2df2d59d698e3aff197a from qemu
2018-02-23 13:52:13 -05:00
Peter Maydell 4ca19f2cd6
tcg: Clean up includes
Clean up includes so that osdep.h is included first and headers
which it implies are not included manually.

This commit was created with scripts/clean-includes.

Backports commit 757e725b58c57d3ebb66a31fd2210df977a12154 from qemu
2018-02-19 01:04:30 -05:00
Lioncash fb2fe4580f
optimize: Add missing extrh/extrl case 2018-02-11 02:57:55 -05:00
Richard Henderson 58e939b91f
tcg: Split trunc_shr_i32 opcode into extr[lh]_i64_i32
Rather than allow arbitrary shift+trunc, only concern ourselves
with low and high parts. This is all that was being used anyway.

Backports commit 609ad70562793937257c89d07bf7c1370b9fc9aa from qemu
2018-02-10 23:00:45 -05:00
Aurelien Jarno 4bd3d5005e
tcg/optimize: add optimizations for ext_i32_i64 and extu_i32_i64 ops
They behave the same as ext32s_i64 and ext32u_i64 from the constant
folding and zero propagation point of view, except that they can't
be replaced by a mov, so we don't compute the affected value.

Backports commit 8bcb5c8f34f9215d4f88f388c7ff14c9bd5cecd3 from qemu
2018-02-10 22:47:26 -05:00
Aurelien Jarno 80223e7ad5
tcg: rename trunc_shr_i32 into trunc_shr_i64_i32
The op is sometimes named trunc_shr_i32 and sometimes trunc_shr_i64_i32,
and the name in the README doesn't match the name offered to the
frontends.

Always use the long name to make it clear it is a size changing op.

Backports commit 0632e555fc4d281d69cb08d98d500d96185b041f from qemu
2018-02-10 22:29:30 -05:00
Aurelien Jarno 5f0920ad0f
tcg/optimize: allow constant to have copies
Now that copies and constants are tracked separately, we can allow
constant to have copies, deferring the choice to use a register or a
constant to the register allocation pass. This prevent this kind of
regular constant reloading:

-OUT: [size=338]
+OUT: [size=298]
   mov    -0x4(%r14),%ebp
   test   %ebp,%ebp
   jne    0x7ffbe9cb0ed6
   mov    $0x40002219f8,%rbp
   mov    %rbp,(%r14)
-  mov    $0x40002219f8,%rbp
   mov    $0x4000221a20,%rbx
   mov    %rbp,(%rbx)
   mov    $0x4000000000,%rbp
   mov    %rbp,(%r14)
-  mov    $0x4000000000,%rbp
   mov    $0x4000221d38,%rbx
   mov    %rbp,(%rbx)
   mov    $0x40002221a8,%rbp
   mov    %rbp,(%r14)
-  mov    $0x40002221a8,%rbp
   mov    $0x4000221d40,%rbx
   mov    %rbp,(%rbx)
   mov    $0x4000019170,%rbp
   mov    %rbp,(%r14)
-  mov    $0x4000019170,%rbp
   mov    $0x4000221d48,%rbx
   mov    %rbp,(%rbx)
   mov    $0x40000049ee,%rbp
   mov    %rbp,0x80(%r14)
   mov    %r14,%rdi
   callq  0x7ffbe99924d0
   mov    $0x4000001680,%rbp
   mov    %rbp,0x30(%r14)
   mov    0x10(%r14),%rbp
   mov    $0x4000001680,%rbp
   mov    %rbp,0x30(%r14)
   mov    0x10(%r14),%rbp
   shl    $0x20,%rbp
   mov    (%r14),%rbx
   mov    %ebx,%ebx
   mov    %rbx,(%r14)
   or     %rbx,%rbp
   mov    %rbp,0x10(%r14)
   mov    %rbp,0x90(%r14)
   mov    0x60(%r14),%rbx
   mov    %rbx,0x38(%r14)
   mov    0x28(%r14),%rbx
   mov    $0x4000220e60,%r12
   mov    %rbx,(%r12)
   mov    $0x40002219c8,%rbx
   mov    %rbp,(%rbx)
   mov    0x20(%r14),%rbp
   sub    $0x8,%rbp
   mov    $0x4000004a16,%rbx
   mov    %rbx,0x0(%rbp)
   mov    %rbp,0x20(%r14)
   mov    $0x19,%ebp
   mov    %ebp,0xa8(%r14)
   mov    $0x4000015110,%rbp
   mov    %rbp,0x80(%r14)
   xor    %eax,%eax
   jmpq   0x7ffbebcae426
   lea    -0x5f6d72a(%rip),%rax        # 0x7ffbe3d437b3
   jmpq   0x7ffbebcae426

Backports commit 299f80130401153af1a6ddb3cc011781bcd47600 from qemu
2018-02-10 22:18:03 -05:00
Aurelien Jarno 59909fe549
tcg/optimize: track const/copy status separately
Instead of using an enum which could be either a copy or a const, track
them separately. This will be used in the next patch.

Constants are tracked through a bool. Copies are tracked by initializing
temp's next_copy and prev_copy to itself, allowing to simplify the code
a bit.

Backports commit b41059dd9deec367a4ccd296659f0bc5de2dc705 from qemu
2018-02-10 22:15:43 -05:00
Aurelien Jarno 134a7dfe82
tcg/optimize: add temp_is_const and temp_is_copy functions
Add two accessor functions temp_is_const and temp_is_copy, to make the
code more readable and make code change easier.

Backports commit d9c769c60948815ee03b2684b1c1c68ee4375149 from qemu
2018-02-10 22:07:02 -05:00
Aurelien Jarno b450b79622
tcg/optimize: optimize temps tracking
The tcg_temp_info structure uses 24 bytes per temp. Now that we emulate
vector registers on most guests, it's not uncommon to have more than 100
used temps. This means we have initialize more than 2kB at least twice
per TB, often more when there is a few goto_tb.

Instead used a TCGTempSet bit array to track which temps are in used in
the current basic block. This means there are only around 16 bytes to
initialize.

This improves the boot time of a MIPS guest on an x86-64 host by around
7% and moves out tcg_optimize from the the top of the profiler list.

Backports commit 1208d7dd5fddc1fbd98de800d17429b4e5578848 from qemu
2018-02-10 21:51:46 -05:00
Aurelien Jarno 5f67ab74e7
tcg/optimize: fix constant signedness
By convention, on a 64-bit host TCG internally stores 32-bit constants
as sign-extended. This is not the case in the optimizer when a 32-bit
constant is folded.

This doesn't seem to have more consequences than suboptimal code
generation. For instance the x86 backend assumes sign-extended constants,
and in some rare cases uses a 32-bit unsigned immediate 0xffffffff
instead of a 8-bit signed immediate 0xff for the constant -1. This is
with a ppc guest:

before
------

 ---- 0x9f29cc
 movi_i32 tmp1,$0xffffffff
 movi_i32 tmp2,$0x0
 add2_i32 tmp0,CA,CA,tmp2,r6,tmp2
 add2_i32 tmp0,CA,tmp0,CA,tmp1,tmp2
 mov_i32 r10,tmp0

0x7fd8c7dfe90c:  xor    %ebp,%ebp
0x7fd8c7dfe90e:  mov    %ebp,%r11d
0x7fd8c7dfe911:  mov    0x18(%r14),%r9d
0x7fd8c7dfe915:  add    %r9d,%r10d
0x7fd8c7dfe918:  adc    %ebp,%r11d
0x7fd8c7dfe91b:  add    $0xffffffff,%r10d
0x7fd8c7dfe922:  adc    %ebp,%r11d
0x7fd8c7dfe925:  mov    %r11d,0x134(%r14)
0x7fd8c7dfe92c:  mov    %r10d,0x28(%r14)

after
-----

 ---- 0x9f29cc
 movi_i32 tmp1,$0xffffffffffffffff
 movi_i32 tmp2,$0x0
 add2_i32 tmp0,CA,CA,tmp2,r6,tmp2
 add2_i32 tmp0,CA,tmp0,CA,tmp1,tmp2
 mov_i32 r10,tmp0

0x7f37010d490c:  xor    %ebp,%ebp
0x7f37010d490e:  mov    %ebp,%r11d
0x7f37010d4911:  mov    0x18(%r14),%r9d
0x7f37010d4915:  add    %r9d,%r10d
0x7f37010d4918:  adc    %ebp,%r11d
0x7f37010d491b:  add    $0xffffffffffffffff,%r10d
0x7f37010d491f:  adc    %ebp,%r11d
0x7f37010d4922:  mov    %r11d,0x134(%r14)
0x7f37010d4929:  mov    %r10d,0x28(%r14)

Backports commit 29f3ff8d6cbc28f79933aeaa25805408d0984a8f from qemu
2018-02-10 21:40:20 -05:00
Aurelien Jarno e273acf87a
tcg/optimize: fix tcg_opt_gen_movi
Due to a copy&paste, the new op value is tested against mov_i32 instead
of movi_i32. The test is therefore always false. Fix that.

Backports commit 961521261a3d600b0695b2e6d2b0f490076f7e90 from qemu
2018-02-10 21:38:09 -05:00
Aurelien Jarno 42dd2addbe
tcg/optimize: rename tcg_constant_folding
The tcg_constant_folding folding ends up doing all the optimizations
(which is a good thing to avoid looping on all ops multiple time), so
make it clear and just rename it tcg_optimize.

Backports commit 36e60ef6ac5d8a262d0fbeedfdb2b588514cb1ea from qemu
2018-02-10 21:36:34 -05:00
Aurelien Jarno 7b0055d742
tcg/optimize: fold constant test in tcg_opt_gen_mov
Most of the calls to tcg_opt_gen_mov are preceeded by a test to check if
the source temp is a constant. Fold that into the tcg_opt_gen_mov
function.

Backports commit 97a79eb70dd35a24fda87d86196afba5e6f21c5d from qemu
2018-02-10 21:34:00 -05:00
Aurelien Jarno 517fac57c3
tcg/optimize: fold temp copies test in tcg_opt_gen_mov
Each call to tcg_opt_gen_mov is preceeded by a test to check if the
source and destination temps are copies. Fold that into the
tcg_opt_gen_mov function.

Backports commit 5365718a9afeeabde3784d82a542f8ad909b18cf from qemu
2018-02-10 21:27:06 -05:00