Chris Lattner
b5906d5783
Change a place to use an arbitrary value instead of null, when possible
...
llvm-svn: 22605
2005-08-02 23:29:23 +00:00
Chris Lattner
b8fd6a098e
This code was very close, but not quite right. It did not take into
...
consideration the case where a reference in an unreachable block could
occur. This fixes Transforms/SimplifyCFG/2005-08-01-PHIUpdateFail.ll,
something I ran into while bugpoint'ing another pass.
llvm-svn: 22584
2005-08-02 03:24:05 +00:00
Chris Lattner
8c76d5c957
Don't crash on: X = phi (X, X).
...
This fixes PR584 and Transforms/SimplifyCFG/2005-06-16-PHICrash.ll
llvm-svn: 22232
2005-06-17 01:45:53 +00:00
Chris Lattner
b13335fff2
Fix Transforms/SimplifyCFG/switch-simplify-crash.ll
...
llvm-svn: 22158
2005-05-20 22:19:54 +00:00
Chris Lattner
214f1a8cf9
Make sure to preserve the calling convention when changing an invoke into
...
a call. This fixes Prolangs-C++/deriv2, kimwitu++, and Misc-C++/bigfib
on X86 with -enable-x86-fastcc.
llvm-svn: 22023
2005-05-14 12:21:56 +00:00
Misha Brukman
53e199440e
Remove trailing whitespace
...
llvm-svn: 21427
2005-04-21 23:48:37 +00:00
Chris Lattner
6ce1b109aa
Teach simplifycfg that setcc is cheap and non-trapping, so that it can
...
convert this:
%tmp.1 = seteq int %i, 0 ; <bool> [#uses=1]
br bool %tmp.1, label %shortcirc_done, label %shortcirc_next
shortcirc_next: ; preds = %entry
%tmp.4 = seteq int %j, 0 ; <bool> [#uses=1]
br label %shortcirc_done
shortcirc_done: ; preds = %shortcirc_next, %entry
%shortcirc_val = phi bool [ %tmp.4, %shortcirc_next ], [ true, %entry ] ; <bool> [#uses=1]
to this:
%tmp.1 = seteq int %i, 0 ; <bool> [#uses=1]
%tmp.4 = seteq int %j, 0 ; <bool> [#uses=1]
%shortcirc_val = select bool %tmp.1, bool true, bool %tmp.4 ; <bool> [#uses=1]
... which is later simplified by instcombine into an or.
llvm-svn: 21388
2005-04-21 05:31:13 +00:00
Chris Lattner
ee06161a63
Get rid of this for_each loop
...
llvm-svn: 21253
2005-04-12 18:51:33 +00:00
Chris Lattner
a024984017
Fix spelling, patch contributed by Gabor Greif!
...
llvm-svn: 20343
2005-02-27 06:18:25 +00:00
Chris Lattner
14f720d625
remove extraneous cast
...
llvm-svn: 20334
2005-02-26 18:33:28 +00:00
Chris Lattner
7a434679c3
Implement Transforms/SimplifyCFG/switch_thread.ll
...
This does a simple form of "jump threading", which eliminates CFG edges that
are provably dead. This triggers 90 times in the external tests, and
eliminating CFG edges is always always a good thing! :)
llvm-svn: 20300
2005-02-24 06:17:52 +00:00
Chris Lattner
ccc0c99fae
switchinst ctor now takes a hint for the number of cases that it will have.
...
llvm-svn: 19898
2005-01-29 00:38:26 +00:00
Chris Lattner
5fff877f74
Implement SimplifyCFG/DeadSetCC.ll
...
SimplifyCFG is one of those passes that we use for final cleanup: it should
not rely on other passes to clean up its garbage. This fixes the "why are
trivially dead setcc's in the output of gccas" problem.
llvm-svn: 19212
2005-01-01 16:02:12 +00:00
Chris Lattner
40e97884f6
Fix Regression/Transforms/SimplifyCFG/2004-12-10-SimplifyCFGCrash.ll,
...
and the failure on make_dparser last night.
llvm-svn: 18766
2004-12-10 17:42:31 +00:00
Chris Lattner
c58bc8d96e
Squelch warning
...
llvm-svn: 18381
2004-11-30 07:47:34 +00:00
Chris Lattner
25b93fea2a
Alkis noticed that this variable is dead. Thanks!
...
llvm-svn: 18369
2004-11-30 04:01:44 +00:00
Chris Lattner
b237a19a78
If we have something like this:
...
if (x) {
code
...
} else {
code
...
}
Turn it into:
code
if (x) {
...
} else {
...
}
This reduces code size and in some common cases allows us to completely
eliminate the conditional. This turns several if/then/else blocks in loops
into straightline code in 179.art, turning the loops into single basic blocks
(good for modsched even!).
Maybe now brg will leave me alone ;-)
llvm-svn: 18366
2004-11-30 00:29:14 +00:00
Chris Lattner
3083f2a424
Do not compute the predecessor list for a block unless we need it.
...
This speeds up simplifycfg on this program, from 44.87s to 0.29s (with
a profiled build):
#define CL0(a) case a: goto c;
#define CL1(a) CL0(a##0) CL0(a##1) CL0(a##2) CL0(a##3) CL0(a##4) CL0(a##5) \
CL0(a##6) CL0(a##7) CL0(a##8) CL0(a##9)
#define CL2(a) CL1(a##0) CL1(a##1) CL1(a##2) CL1(a##3) CL1(a##4) CL1(a##5) \
CL1(a##6) CL1(a##7) CL1(a##8) CL1(a##9)
#define CL3(a) CL2(a##0) CL2(a##1) CL2(a##2) CL2(a##3) CL2(a##4) CL2(a##5) \
CL2(a##6) CL2(a##7) CL2(a##8) CL2(a##9)
#define CL4(a) CL3(a##0) CL3(a##1) CL3(a##2) CL3(a##3) CL3(a##4) CL3(a##5) \
CL3(a##6) CL3(a##7) CL3(a##8) CL3(a##9)
void f();
void a() {
int b;
c: switch (b) {
CL4(1)
}
}
This testcase is contrived to expose N^2 behavior, but this patch should speedup
simplifycfg on any programs that use large switch statements. This testcase
comes from GCC PR17895.
llvm-svn: 17389
2004-11-01 06:53:58 +00:00
Reid Spencer
9f6f128630
Eliminate compilation warning on uninitialized variable.
...
llvm-svn: 17163
2004-10-22 16:10:39 +00:00
Chris Lattner
b1827a765a
Simplify code by deleting instructions that preceed unreachable instructions.
...
Simplify code by simplifying terminators that branch to blocks that start
with an unreachable instruction.
llvm-svn: 17116
2004-10-18 04:07:22 +00:00
Chris Lattner
88ad718c75
When converting phi nodes into select instructions, we shouldn't promote PHI
...
nodes unless we KNOW that we are able to promote all of them.
This fixes: test/Regression/Transforms/SimplifyCFG/PhiNoEliminate.ll
llvm-svn: 16973
2004-10-14 05:13:36 +00:00
Chris Lattner
778a49acfd
Do not insert trivially dead select instructions, which allows us to
...
potentially fold more in one pass.
llvm-svn: 16583
2004-09-29 05:43:32 +00:00
Reid Spencer
c6a8d70cff
Convert code to compile with vc7.1.
...
Patch contributed by Paolo Invernizzi. Thanks Paolo!
llvm-svn: 16368
2004-09-15 17:06:42 +00:00
Alkis Evlogimenos
0c50e0f211
Fixes to make LLVM compile with vc7.1.
...
Patch contributed by Paolo Invernizzi!
llvm-svn: 16152
2004-09-03 18:19:51 +00:00
Reid Spencer
c4abcbefb1
Changes For Bug 352
...
Move include/Config and include/Support into include/llvm/Config,
include/llvm/ADT and include/llvm/Support. From here on out, all LLVM
public header files must be under include/llvm/.
llvm-svn: 16137
2004-09-01 22:55:40 +00:00
Brian Gaeke
f18cdca667
These files don't need to include <iostream> since they include "Support/Debug.h".
...
llvm-svn: 15089
2004-07-21 20:50:33 +00:00
Chris Lattner
8277141f09
Implement SimplifyCFG/BrUnwind.ll
...
llvm-svn: 15022
2004-07-20 01:17:38 +00:00
Reid Spencer
51149979ce
bug 122:
...
- Minimize redundant isa<GlobalValue> usage
llvm-svn: 14948
2004-07-18 00:32:14 +00:00
Chris Lattner
2db1894038
Progress on PR341
...
llvm-svn: 14840
2004-07-15 02:06:12 +00:00
Reid Spencer
50ec3f9325
Add #include <iostream> since Value.h does not #include it any more.
...
llvm-svn: 14622
2004-07-04 12:19:56 +00:00
Chris Lattner
97ab2cec69
*FINALLY* Fix a really nasty nondeterministic bug that has been haunting us
...
since May 1st. In this code, the pred iterator was being invalidated sometimes
causing the wrong entries to be added to PHI nodes.
The fix for this is to defererence and safe the *PI value before we hack on
branch instructions, which changes use/def chains, which SOMETIMES invalidates
the iterator.
llvm-svn: 14278
2004-06-21 07:19:01 +00:00
Chris Lattner
58b3f16797
Add some DEBUG output to the simplifycfg routines
...
Fix another non-deterministic behavior, this one should actually speed up the
code though as it was doing silly things.
llvm-svn: 14258
2004-06-20 01:13:18 +00:00
Chris Lattner
6e7b76ce94
Do not sort by the address of LLVM ConstantInt* objects. This produces
...
nondeterministic results that depend on where these objects land in memory.
Instead, sort by the value of the constant, which is stable.
Before this patch, the -simplifycfg pass run from two different compilers
could cause different code to be generated, though it was semantically the
same:
@@ -12258,8 +12258,8 @@
%s_addr.1 = phi sbyte* [ %s, %entry ], [ %inc.0, %no_exit ] ; <sbyte*> [#uses=5]
%tmp.1 = load sbyte* %s_addr.1 ; <sbyte> [#uses=1]
switch sbyte %tmp.1, label %no_exit [
- sbyte 0, label %loopexit
sbyte 46, label %loopexit
+ sbyte 0, label %loopexit
]
We need to stomp all of this stuff out.
llvm-svn: 14243
2004-06-19 07:02:14 +00:00
Chris Lattner
d8345001fa
Do not clone arbitrary condition instructions.
...
llvm-svn: 13316
2004-05-02 05:19:36 +00:00
Chris Lattner
da2d746a3b
Do not infinitely "unroll" single BB loops.
...
llvm-svn: 13315
2004-05-02 05:02:03 +00:00
Chris Lattner
5f393764c8
Dont' merge terminators that are needed to select PHI node values.
...
llvm-svn: 13312
2004-05-02 01:00:44 +00:00
Chris Lattner
bd705d7776
Implement SimplifyCFG/branch-cond-merge.ll
...
Turning "if (A < B && B < C)" into "if (A < B & B < C)"
llvm-svn: 13311
2004-05-01 23:35:43 +00:00
Chris Lattner
911e21e8ca
Fix my missing parens
...
llvm-svn: 13307
2004-05-01 22:41:51 +00:00
Chris Lattner
82278b599b
Implement SimplifyCFG/branch-cond-prop.ll
...
llvm-svn: 13306
2004-05-01 22:36:37 +00:00
Chris Lattner
8ccddbd123
Fold code like:
...
if (C)
V1 |= V2;
into:
Vx = V1 | V2;
V1 = select C, V1, Vx
when the expression can be evaluated unconditionally and is *cheap* to
execute. This limited form of if conversion is quite handy in lots of cases.
For example, it turns this testcase into straight-line code:
int in0 ; int in1 ; int in2 ; int in3 ;
int in4 ; int in5 ; int in6 ; int in7 ;
int in8 ; int in9 ; int in10; int in11;
int in12; int in13; int in14; int in15;
long output;
void mux(void) {
output =
(in0 ? 0x00000001 : 0) | (in1 ? 0x00000002 : 0) |
(in2 ? 0x00000004 : 0) | (in3 ? 0x00000008 : 0) |
(in4 ? 0x00000010 : 0) | (in5 ? 0x00000020 : 0) |
(in6 ? 0x00000040 : 0) | (in7 ? 0x00000080 : 0) |
(in8 ? 0x00000100 : 0) | (in9 ? 0x00000200 : 0) |
(in10 ? 0x00000400 : 0) | (in11 ? 0x00000800 : 0) |
(in12 ? 0x00001000 : 0) | (in13 ? 0x00002000 : 0) |
(in14 ? 0x00004000 : 0) | (in15 ? 0x00008000 : 0) ;
}
llvm-svn: 12798
2004-04-09 22:50:22 +00:00
Chris Lattner
3f202e3a54
Fix the obvious bug in my previous checkin
...
llvm-svn: 12618
2004-04-02 18:15:10 +00:00
Chris Lattner
bca948c99d
Implement Transforms/SimplifyCFG/return-merge.ll
...
This actually causes us to turn code like:
return C ? A : B;
into a select instruction.
llvm-svn: 12617
2004-04-02 18:13:43 +00:00
Chris Lattner
145aea5c4c
Now that all the code generators support the select instruction, and the instcombine
...
pass can eliminate many nasty cases of them, start generating them in the optimizers
llvm-svn: 12545
2004-03-30 19:44:05 +00:00
Chris Lattner
849234af99
Fix compilation of mesa, which I broke earlier today
...
llvm-svn: 12465
2004-03-17 02:02:47 +00:00
Chris Lattner
2175b35b46
Do not copy gigantic switch instructions
...
llvm-svn: 12441
2004-03-16 19:45:22 +00:00
Chris Lattner
a854ddd528
Implement switch->br and br->switch folding by ripping out the switch->switch
...
and br->br code and generalizing it. This allows us to compile code like this:
int test(Instruction *I) {
if (isa<CastInst>(I))
return foo(7);
else if (isa<BranchInst>(I))
return foo(123);
else if (isa<UnwindInst>(I))
return foo(1241);
else if (isa<SetCondInst>(I))
return foo(1);
else if (isa<VAArgInst>(I))
return foo(42);
return foo(-1);
}
into:
int %_Z4testPN4llvm11InstructionE("struct.llvm::Instruction"* %I) {
entry:
%tmp.1.i.i.i.i.i.i.i = getelementptr "struct.llvm::Instruction"* %I, long 0, ubyte 4 ; <uint*> [#uses=1]
%tmp.2.i.i.i.i.i.i.i = load uint* %tmp.1.i.i.i.i.i.i.i ; <uint> [#uses=2]
%tmp.2.i.i.i.i.i.i = seteq uint %tmp.2.i.i.i.i.i.i.i, 27 ; <bool> [#uses=0]
switch uint %tmp.2.i.i.i.i.i.i.i, label %endif.0 [
uint 27, label %then.0
uint 2, label %then.1
uint 5, label %then.2
uint 14, label %then.3
uint 15, label %then.3
uint 16, label %then.3
uint 17, label %then.3
uint 18, label %then.3
uint 19, label %then.3
uint 32, label %then.4
]
...
As well as handling the cases in 176.gcc and many other programs more effectively.
llvm-svn: 11964
2004-02-28 21:28:10 +00:00
Chris Lattner
e07d786aa6
turn things like:
...
if (X == 0 || X == 2)
...where the comparisons and branches are in different blocks... into a switch
instruction. This comes up a lot in various programs, and works well with
the switch/switch merging code I checked earlier. For example, this testcase:
int switchtest(int C) {
return C == 0 ? f(123) :
C == 1 ? f(3123) :
C == 4 ? f(312) :
C == 5 ? f(1234): f(444);
}
is converted into this:
switch int %C, label %cond_false.3 [
int 0, label %cond_true.0
int 1, label %cond_true.1
int 4, label %cond_true.2
int 5, label %cond_true.3
]
instead of a whole bunch of conditional branches.
Admittedly the code is ugly, and incomplete. To be complete, we need to add
br -> switch merging and switch -> br merging. For example, this testcase:
struct foo { int Q, R, Z; };
#define A (X->Q+X->R * 123)
int test(struct foo *X) {
return A == 123 ? X1() :
A == 12321 ? X2():
(A == 111 || A == 222) ? X3() :
A == 875 ? X4() : X5();
}
Gets compiled to this:
switch int %tmp.7, label %cond_false.2 [
int 123, label %cond_true.0
int 12321, label %cond_true.1
int 111, label %cond_true.2
int 222, label %cond_true.2
]
...
cond_false.2: ; preds = %entry
%tmp.52 = seteq int %tmp.7, 875 ; <bool> [#uses=1]
br bool %tmp.52, label %cond_true.3, label %cond_false.3
where the branch could be folded into the switch.
This kind of thing occurs *ALL OF THE TIME*, especially in programs like
176.gcc, which is a horrible mess of code. It contains stuff like *shudder*:
#define SWITCH_TAKES_ARG(CHAR) \
( (CHAR) == 'D' \
|| (CHAR) == 'U' \
|| (CHAR) == 'o' \
|| (CHAR) == 'e' \
|| (CHAR) == 'u' \
|| (CHAR) == 'I' \
|| (CHAR) == 'm' \
|| (CHAR) == 'L' \
|| (CHAR) == 'A' \
|| (CHAR) == 'h' \
|| (CHAR) == 'z')
and
#define CONST_OK_FOR_LETTER_P(VALUE, C) \
((C) == 'I' ? SMALL_INTVAL (VALUE) \
: (C) == 'J' ? SMALL_INTVAL (-(VALUE)) \
: (C) == 'K' ? (unsigned)(VALUE) < 32 \
: (C) == 'L' ? ((VALUE) & 0xffff) == 0 \
: (C) == 'M' ? integer_ok_for_set (VALUE) \
: (C) == 'N' ? (VALUE) < 0 \
: (C) == 'O' ? (VALUE) == 0 \
: (C) == 'P' ? (VALUE) >= 0 \
: 0)
and
#define LEGITIMIZE_ADDRESS(X,OLDX,MODE,WIN) \
{ \
if (GET_CODE (X) == PLUS && CONSTANT_ADDRESS_P (XEXP (X, 1))) \
(X) = gen_rtx (PLUS, SImode, XEXP (X, 0), \
copy_to_mode_reg (SImode, XEXP (X, 1))); \
if (GET_CODE (X) == PLUS && CONSTANT_ADDRESS_P (XEXP (X, 0))) \
(X) = gen_rtx (PLUS, SImode, XEXP (X, 1), \
copy_to_mode_reg (SImode, XEXP (X, 0))); \
if (GET_CODE (X) == PLUS && GET_CODE (XEXP (X, 0)) == MULT) \
(X) = gen_rtx (PLUS, SImode, XEXP (X, 1), \
force_operand (XEXP (X, 0), 0)); \
if (GET_CODE (X) == PLUS && GET_CODE (XEXP (X, 1)) == MULT) \
(X) = gen_rtx (PLUS, SImode, XEXP (X, 0), \
force_operand (XEXP (X, 1), 0)); \
if (GET_CODE (X) == PLUS && GET_CODE (XEXP (X, 0)) == PLUS) \
(X) = gen_rtx (PLUS, Pmode, force_operand (XEXP (X, 0), NULL_RTX),\
XEXP (X, 1)); \
if (GET_CODE (X) == PLUS && GET_CODE (XEXP (X, 1)) == PLUS) \
(X) = gen_rtx (PLUS, Pmode, XEXP (X, 0), \
force_operand (XEXP (X, 1), NULL_RTX)); \
if (GET_CODE (X) == SYMBOL_REF || GET_CODE (X) == CONST \
|| GET_CODE (X) == LABEL_REF) \
(X) = legitimize_address (flag_pic, X, 0, 0); \
if (memory_address_p (MODE, X)) \
goto WIN; }
and others. These macros get used multiple times of course. These are such
lovely candidates for macros, aren't they? :)
This code also nicely handles LLVM constructs that look like this:
if (isa<CastInst>(I))
...
else if (isa<BranchInst>(I))
...
else if (isa<SetCondInst>(I))
...
else if (isa<UnwindInst>(I))
...
else if (isa<VAArgInst>(I))
...
where the isa can obviously be a dyn_cast as well. Switch instructions are a
good thing.
llvm-svn: 11870
2004-02-26 07:13:46 +00:00
Chris Lattner
7845e4f7f0
If a block is made dead, make sure to promptly remove it.
...
llvm-svn: 11799
2004-02-24 16:09:21 +00:00
Chris Lattner
d678669018
Implement SimplifyCFG/switch_switch_fold.ll
...
This case occurs many times in various benchmarks, especially when combined
with the previous patch. This allows it to get stuff like:
if (X == 4 || X == 3)
if (X == 5 || X == 8)
and
switch (X) {
case 4: case 5: case 6:
if (X == 4 || X == 5)
llvm-svn: 11797
2004-02-24 07:23:58 +00:00
Chris Lattner
1293e1d00c
Rearrange code a bit
...
llvm-svn: 11793
2004-02-24 05:54:22 +00:00