In case of using 32-bit GOT access to the table requires two instructions
with attached %got_hi and %got_lo relocations. This patch implements
correct expansion of 'lw/sw' instructions in that case.
Differential Revision: https://reviews.llvm.org/D67705
llvm-svn: 372251
When a "base" in the `lw/sw $reg1, symbol($reg2)` instruction is
a register and generated code is position independent, backend
does not add the "base" value to the symbol address.
```
lw $reg1, %got(symbol)($gp)
lw/sw $reg1, 0($reg1)
```
This patch fixes the bug and adds the missed `addu` instruction by
passing `BaseReg` into the `loadAndAddSymbolAddress` routine and handles
the case when the `BaseReg` is the zero register to escape redundant
`move reg, reg` instruction:
```
lw $reg1, %got(symbol)($gp)
addu $reg1, $reg1, $reg2
lw/sw $reg1, 0($reg1)
```
Differential Revision: https://reviews.llvm.org/D66894
llvm-svn: 370353
Now `lw/sw $reg, sym+offset` pseudo instructions for global symbol `sym`
are lowering into the following three instructions.
```
lw $reg, %got(symbol)($gp)
addiu $reg, $reg, offset
lw/sw $reg, 0($reg)
```
It's possible to reduce the number of instructions by taking the offset
in account in the final `lw/sw` command. This patch implements that
optimization.
```
lw $reg, %got(symbol)($gp)
lw/sw $reg, offset($reg)
```
Differential Revision: https://reviews.llvm.org/D66553
llvm-svn: 369756
Now pseudo instruction `la $6, symbol+8($6)` is expanding into the following
chain of commands:
```
lw $1, %got(symbol+8)($gp)
addiu $1, $1, 8
addu $6, $1, $6
```
This is incorrect. When a linker handles the `R_MIPS_GOT16` relocation,
it does not expect to get any addend and breaks on assertion. Otherwise
it has to create new GOT entry for each unique "sym + offset" pair.
Offset for a global symbol should be added to result of loading GOT
entry by a separate `add` command.
The patch fixes the problem by stripping off an offset from the expression
passed to the `%got`. That's interesting that even current code inserts
a separate `add` command.
Differential Revision: https://reviews.llvm.org/D66552
llvm-svn: 369755
If an operand of the `lw/sw` instructions is a symbol, these instructions
incorrectly lowered using not-position-independent chain of commands.
For PIC code we should use `lw/addiu` instructions with the `R_MIPS_GOT16`
and `R_MIPS_LO16` relocations respectively. Instead of that LLVM generates
position dependent code with the `R_MIPS_HI16` and `R_MIPS_LO16`
relocations.
This patch provides a fix for the bug by handling PIC case separately in
the `MipsAsmParser::expandMemInst`. The main idea is to generate a chain
of PIC instructions to load a symbol address into a register and then
load the address content.
The fix is not optimal and does not fix all PIC-related problems. This
is a task for subsequent patches.
Differential Revision: https://reviews.llvm.org/D65524
llvm-svn: 367580
This is a follow up to the rL330983. The patch teaches lh and lhu
commands accepts 32-bit memory offsets by replacing `mem_simm16` operand
to `mem_simmptr`.
Differential Revision: https://reviews.llvm.org/D46513
llvm-svn: 331996
`lb` and `lbu` commands accepts 16-bit signed offsets. But GAS accepts
larger offsets for these commands. If an offset does not fit in 16-bit
range, `lb` command is translated into lui/lb or lui/addu/lb series.
It's interesting that initially LLVM assembler supported this feature,
but later it was broken.
This patch restores support for 32-bit offsets. It replaces `mem_simm16`
operand for `LB` and `LBu` definitions by the new `mem_simmptr` operand.
This operand is intended to check that offset fits to the same size as
using for pointers. Later we will be able to extend this rule and
accepts 64-bit offsets when it is possible.
Some issues remain:
- The regression also affects LD, SD, LH, LHU commands. I'm going
to fix them by a separate patch.
- GAS accepts any 32-bit values as an offset. Now LLVM accepts signed
16-bit values and this patch extends the range to signed 32-bit offsets.
In other words, the following code accepted by GAS and still triggers
an error by LLVM:
```
lb $4, 0x80000004
# gas
lui a0, 0x8000
lb a0, 4(a0)
```
- In case of 64-bit pointers GAS accepts a 64-bit offset and translates
it to the li/dsll/lb series of commands. LLVM still rejects it.
Probably this feature has never been implemented in LLVM. This issue
is for a separate patch.
```
lb $4, 0x800000001
# gas
li a0, 0x8000
dsll a0, a0, 0x14
lb a0, 4(a0)
```
Differential Revision: https://reviews.llvm.org/D45020
llvm-svn: 330983
Add missing unaligned store macros (ush/usw) and fix the exisiting
implementation of the unaligned load macros in order to generate
identical expansions with the GNU assembler.
llvm-svn: 287646
Summary:
This is much closer to the way MIPS relocation expressions work
(%hi(foo + 2) rather than %hi(foo) + 2) and removes the need for the
various bodges in MipsAsmParser::evaluateRelocExpr().
Removing those bodges ensures that the constant stored in MCValue is the
full 32 or 64-bit (depending on ABI) offset from the symbol. This will be used
to correct the %hi/%lo matching needed to sort the relocation table correctly.
As part of this:
* Gave MCExpr::print() the ability to omit parenthesis when emitting a
symbol reference inside a MipsMCExpr operator like %hi(X). Without this
we print things like %lo(($L1)).
* %hi(%neg(%gprel(X))) is now three MipsMCExpr's instead of one. Most of
the related special cases have been removed or moved to MipsMCExpr. We
can remove the rest as we gain support for the less common relocations
when they are not part of this specific combination.
* Renamed MipsMCExpr::VariantKind and the enum prefix ('VK_') to avoid confusion
with MCSymbolRefExpr::VariantKind and its prefix (also 'VK_').
* fixup_Mips_GOT_Local and fixup_Mips_GOT_Global were found to be identical
and merged into fixup_Mips_GOT.
* MO_GOT16 and MO_GOT turned out to be identical and have been merged into
MO_GOT.
* VK_Mips_GOT and VK_Mips_GOT16 turned out to be the same thing so they
have been merged into MEK_GOT
Reviewers: sdardis
Subscribers: dsanders, sdardis, llvm-commits
Differential Revision: http://reviews.llvm.org/D19716
llvm-svn: 268379
Summary:
The portion in MipsAsmParser is responsible for figuring out which expansion to
use, while the portion in MipsTargetStreamer is responsible for emitting it.
This allows us to remove the call to isIntegratedAssemblerRequired() which is
currently ensuring the effect of .cprestore only occurs when writing objects.
The small functional change is that the memory offsets are now correctly
printed as signed values.
Reviewers: sdardis
Subscribers: dsanders, sdardis, llvm-commits
Differential Revision: http://reviews.llvm.org/D19714
llvm-svn: 268042
Summary:
This macro is needed to prevent test/CodeGen/Mips/2008-08-01-AsmInline.ll from
failing after the integrated assembler is enabled by default.
Reviewers: vkalintiris
Subscribers: llvm-commits, dsanders
Differential Revision: http://reviews.llvm.org/D13654
llvm-svn: 250414
Summary:
An instruction like "(d)la $5, symbol+8" previously would have crashed the
assembler as it contains an expression. This is now fixed.
A few tests cases have also been changed to reflect these changes, however
these should only be syntax changes. Some new test cases have also been
added.
Patch by Scott Egerton.
Reviewers: vkalintiris, dsanders
Subscribers: llvm-commits
Differential Revision: http://reviews.llvm.org/D12760
llvm-svn: 249311
Summary:
- Signed 16-bit should have priority over unsigned.
- For la, unsigned 16-bit must use ori+addu rather than directly use ori.
- Correct tests on 32-bit immediates with 64-bit predicates by
sign-extending the immediate beforehand. For example, isInt<16>(0xffff8000)
should be true and use addiu.
Also split li/la testing into separate files due to their size.
Reviewers: vkalintiris
Subscribers: llvm-commits
Differential Revision: http://reviews.llvm.org/D10967
llvm-svn: 242139
Summary:
This only adds support for ULW of an immediate address with/without a source register.
It does not include support for ULW of the address of a symbol.
Reviewers: dsanders
Reviewed By: dsanders
Subscribers: llvm-commits
Differential Revision: http://reviews.llvm.org/D9663
llvm-svn: 240782
Summary:
This only adds support for ULHU of an immediate address with/without a source register.
It does not include support for ULHU of the address of a symbol.
Reviewers: dsanders
Reviewed By: dsanders
Subscribers: llvm-commits
Differential Revision: http://reviews.llvm.org/D9671
llvm-svn: 240410
Summary: In this case, we're supposed to load the immediate in AT and then ADDu it with the source register and put it in the destination register.
Reviewers: dsanders
Reviewed By: dsanders
Subscribers: llvm-commits
Differential Revision: http://reviews.llvm.org/D9367
llvm-svn: 240278
Summary:
In this case, we're supposed to load the address of the symbol in AT and then ADDu it with the source register and
put it in the destination register.
Reviewers: dsanders
Reviewed By: dsanders
Subscribers: llvm-commits
Differential Revision: http://reviews.llvm.org/D9366
llvm-svn: 240273
Summary:
Call MCSymbolRefExpr::create() with a MCSymbol* argument, not with a StringRef
of the Symbol's name, in order to avoid creating invalid temporary symbols for
relative labels (e.g. {$,.L}tmp00, {$,.L}tmp10 etc.).
Reviewers: dsanders
Reviewed By: dsanders
Subscribers: llvm-commits
Differential Revision: http://reviews.llvm.org/D10498
llvm-svn: 239901
Summary:
Previously, MCSymbolRefExpr::create() was called with a StringRef of the symbol
name, which it would then search for in the Symbols StringMap (from MCContext).
However, relative labels (which are temporary symbols) are apparently not stored
in the Symbols StringMap, so we end up creating a new {$,.L}tmp symbol
({$,.L}tmp00, {$,.L}tmp10 etc.) each time we create an MCSymbolRefExpr by
passing in the symbol name as a StringRef.
Fortunately, there is a version of MCSymbolRefExpr::create() which takes an
MCSymbol* and we already have an MCSymbol* at that point, so we can just pass
that in instead of the StringRef.
I also removed the local StringRef calls to MCSymbolRefExpr::create() from
expandMemInst(), as those cases can be handled by evaluateRelocExpr() anyway.
Reviewers: dsanders
Reviewed By: dsanders
Subscribers: llvm-commits
Differential Revision: http://reviews.llvm.org/D9938
llvm-svn: 239897
Summary:
For some branches, GAS accepts an immediate instead of the 2nd register operand.
We only implement this for BNE and BEQ for now. Other branch instructions can be added later, if needed.
Reviewers: dsanders
Reviewed By: dsanders
Subscribers: seanbruno, emaste, llvm-commits
Differential Revision: http://reviews.llvm.org/D9666
llvm-svn: 239396
Summary:
Make mips-expansions.s more readable by grouping the instructions with their respective CHECK's.
This test is going to get a lot bigger soon and it will become essentially unreadable if the current formatting is kept.
I've also made the comments more useful and accurate, and I've restricted the RUN lines to under 80 columns.
Reviewers: dsanders
Reviewed By: dsanders
Subscribers: llvm-commits
Differential Revision: http://reviews.llvm.org/D10089
llvm-svn: 238817
Summary:
To maintain compatibility with GAS, we need to stop treating negative 32-bit immediates as 64-bit values when expanding LI/DLI.
This currently happens because of sign extension.
To do this we need to choose the 32-bit value expansion for values which use their upper 33 bits only for sign extension (i.e. no 0's, only 1's).
Reviewers: dsanders
Reviewed By: dsanders
Subscribers: llvm-commits
Differential Revision: http://reviews.llvm.org/D8662
llvm-svn: 237428
Summary: A side-effect of this is that LA gains proper handling of unsigned and positive signed 16-bit immediates and more accurate error messages.
Reviewers: dsanders
Reviewed By: dsanders
Subscribers: llvm-commits
Differential Revision: http://reviews.llvm.org/D9290
llvm-svn: 237255
Summary: If the immediate is 0, the ORi is pointless.
Reviewers: dsanders
Reviewed By: dsanders
Subscribers: llvm-commits
Differential Revision: http://reviews.llvm.org/D8969
llvm-svn: 235990
Summary:
Even though there is no 2nd register operand in the "lw/sw $8, symbol" case, we still try to find one,
and we end up with $0, which makes us generate an unnecessary "addu $8, $8, $0" (a.k.a. "move $8, $8").
We can avoid this by checking if the 2nd register operand is different from $0, before generating the addu.
Reviewers: dsanders
Reviewed By: dsanders
Subscribers: llvm-commits
Differential Revision: http://reviews.llvm.org/D8055
llvm-svn: 234406
Summary:
This pseudo-instruction allows the programmer to load an address from a symbolic expression into a register.
Patch by David Chisnall.
His work was sponsored by: DARPA, AFRL
I've made some minor changes to the original, such as improving the formatting and adding some comments, and I've also added a test case.
Reviewers: dsanders
Reviewed By: dsanders
Differential Revision: http://reviews.llvm.org/D4808
llvm-svn: 215630
Summary:
The assembler tries to reuse the destination register for memory operations whenever
it can but it's not possible to do so if the destination register is not a GPR.
Example:
ldc1 $f0, sym
should expand to:
lui $at, %hi(sym)
ldc1 $f0, %lo(sym)($at)
It's entirely wrong to expand to:
lui $f0, %hi(sym)
ldc1 $f0, %lo(sym)($f0)
Reviewers: dsanders
Reviewed By: dsanders
Differential Revision: http://reviews.llvm.org/D4173
llvm-svn: 211169
Summary:
This patch doesn't really change the logic behind expandMemInst but it allows
us to assemble .S files that use .set noat with some macros. For example:
.set noat
lw $k0, offset($k1)
Can expand to:
lui $k0, %hi(offset)
addu $k0, $k0, $k1
lw $k0, %lo(offset)($k0)
with no need to access $at.
Reviewers: dsanders, vmedic
Reviewed By: dsanders, vmedic
Differential Revision: http://reviews.llvm.org/D4159
llvm-svn: 211165
This patch uses the generated instruction info tables to
identify memory/load store instructions.
After successful matching and based on the operand type
and size, it generates additional instructions to the output.
Contributor: Vladimir Medic
llvm-svn: 177685
This patch provides initial implementation of load address
macro instruction for Mips. We have implemented two kinds
of expansions with their variations depending on the size
of immediate operand:
1) load address with immediate value directly:
* la d,j => addiu d,$zero,j (for -32768 <= j <= 65535)
* la d,j => lui d,hi16(j)
ori d,d,lo16(j) (for any other 32 bit value of j)
2) load load address with register offset value
* la d,j(s) => addiu d,s,j (for -32768 <= j <= 65535)
* la d,j(s) => lui d,hi16(j) (for any other 32 bit value of j)
ori d,d,lo16(j)
addu d,d,s
This patch does not cover the case when the address is loaded
from the value of the label or function.
Contributer: Vladimir Medic
llvm-svn: 165561
macro instruction (li) in the assembler.
We have identified three possible expansions depending on
the size of immediate operand:
1) for 0 ≤ j ≤ 65535.
li d,j =>
ori d,$zero,j
2) for −32768 ≤ j < 0.
li d,j =>
addiu d,$zero,j
3) for any other value of j that is representable as a 32-bit integer.
li d,j =>
lui d,hi16(j)
ori d,d,lo16(j)
All of the above have been implemented in ths patch.
Contributer: Vladimir Medic
llvm-svn: 165199
Simon Atanasyan