similar to: [LLVMdev] Question about Constant Expressions

Displaying 20 results from an estimated 6000 matches similar to: "[LLVMdev] Question about Constant Expressions"

2010 Nov 23
1
[LLVMdev] Unrolling loops into constant-time expressions
Hello, I've come across another example: I'm compiling with clang -S -emit-llvm -std=gnu99 -O3 clang version 2.9 (trunk 118238) Target: x86_64-unknown-linux-gnu Thread model: posix I take the code: int loops(int x) { int ret = 0; for(int i = 0; i < x; i++) { for(int j = 0; j < x; j++) { ret += 1; } } return ret; } and the
2008 Feb 16
0
[LLVMdev] linux/x86-64 codegen support
libcpp/charset.c:631 turns into: %tmp16 = tail call i64 @strlen( i8* %to ) nounwind readonly ; <i64> [#uses=1] %tmp18 = tail call i64 @strlen( i8* %from ) nounwind readonly ; <i64> [#uses=1] %tmp19 = add i64 %tmp16, 2 ; <i64> [#uses=1] %tmp20 = add i64 %tmp19, %tmp18 ; <i64> [#uses=1] %tmp21 = tail
2011 Oct 06
2
[LLVMdev] A potential bug
Hi all, There might be a bug in DeadStoreElimination.cpp. This pass eliminates stores backwards aggressively in an end BB. It does not check dependencies on stores in an end BB though. For example, in this code snippet: ... 1. %sum.safe_r47.pre-phi = phi i64* [ %sum.safe_r47.pre, %entry.for.end_crit_edge ], [ %sum.safe_r42, %for.body ] 2. %call9 = call i32 @gettimeofday(%struct.timeval* %end,
2007 Jun 12
3
[LLVMdev] ARM backend problem ?
Hello, I want to compile a LLVM file into an executable running on ARM platform. I use LLVM 2.0 with the following command lines: llvm-as -f -o test.bc test.ll llc -march=arm -mcpu=arm1136j-s -mattr=+v6 -f -o test.s test.bc arm-linux-gnu-as -mcpu=arm1136j-s test.s With the last command, I obtain the following error: rd and rm should be different in mul The bad instruction is
2011 Oct 06
2
[LLVMdev] A potential bug
On Thu, Oct 6, 2011 at 2:20 PM, Eli Friedman <eli.friedman at gmail.com> wrote: > On Thu, Oct 6, 2011 at 2:12 PM, Zeng Bin <ezengbin at gmail.com> wrote: >> Hi all, >> >> There might be a bug in DeadStoreElimination.cpp. This pass eliminates >> stores backwards aggressively in an end BB. It does not check dependencies >> on stores in an end BB though.
2011 Oct 06
0
[LLVMdev] A potential bug
On Thu, Oct 6, 2011 at 2:12 PM, Zeng Bin <ezengbin at gmail.com> wrote: > Hi all, > > There might be a bug in DeadStoreElimination.cpp. This pass eliminates > stores backwards aggressively in an end BB. It does not check dependencies > on stores in an end BB though. For example, in this code snippet: >   ... > 1.  %sum.safe_r47.pre-phi = phi i64* [ %sum.safe_r47.pre,
2007 Jun 12
0
[LLVMdev] ARM backend problem ?
Hi Mikael, You are obtaining warning, not an error, right? The most arm cores, including arm1136, can execute mul with rd = rm. So, you can ignore this warning. Lauro 2007/6/12, Peltier, Mikael <m-peltier at ti.com>: > > > > > Hello, > > > > I want to compile a LLVM file into an executable running on ARM platform. > > I use LLVM 2.0 with the following
2011 Oct 06
0
[LLVMdev] A potential bug
It does not do anything. It is an abstract function which transforms a pointer and returns another pointer of the same type. It does not visit memory or capture the pointer parameter. On Thu, Oct 6, 2011 at 2:22 PM, Eli Friedman <eli.friedman at gmail.com> wrote: > On Thu, Oct 6, 2011 at 2:20 PM, Eli Friedman <eli.friedman at gmail.com> > wrote: > > On Thu, Oct 6, 2011 at
2007 Jul 04
1
[LLVMdev] Question about Constant Expressions
Chris: It was in the 1.5 release but not subsequent to that. You can find this by looking for the file in the branches that were converted from subversion. You can find the file you're looking for here: http://llvm.org/viewvc/llvm-project/llvm/branches/release_15/lib/Transforms/Scalar/LowerConstantExprs.cpp?view=log Reid. On Tue, 2007-07-03 at 14:29 -0700, Chris Lattner wrote: > On
2011 Oct 06
1
[LLVMdev] A potential bug
If int_guard_load returns a pointer based on the passed-in pointer, it captures it (at least according to the definition of "capture" which NoCapture uses). -Eli On Thu, Oct 6, 2011 at 2:26 PM, Zeng Bin <ezengbin at gmail.com> wrote: > It does not do anything. It is an abstract function which transforms a > pointer and returns another pointer of the same type. It does not
2007 Jul 03
0
[LLVMdev] Question about Constant Expressions
On Tue, 3 Jul 2007, Ben Chambers wrote: > How hard would it be to compile this pass and add it to the passes > that opt can run? Is this something I should be able to do relatively > quickly? What was the name of the file(s) that implemented the pass? It should be easy, modulo it bitrotting. It is already built as an opt pass. The filename was LowerConstantExpr.cpp IIRC. -Chris
2007 Jul 03
2
[LLVMdev] Question about Constant Expressions
How hard would it be to compile this pass and add it to the passes that opt can run? Is this something I should be able to do relatively quickly? What was the name of the file(s) that implemented the pass? Thanks, Ben On 7/3/07, Chris Lattner <sabre at nondot.org> wrote: > On Tue, 3 Jul 2007, Anton Korobeynikov wrote: > >> We used to have a 'lowerconstantexpr' pass in
2008 Feb 16
2
[LLVMdev] linux/x86-64 codegen support
Interestingly, in the .i file there are 2 __builtin_alloca, and EmitBuiltinAlloca is only being called once. Andrew On 2/16/08, Andrew Lenharth <andrewl at lenharth.org> wrote: > libcpp/charset.c:631 turns into: > > %tmp16 = tail call i64 @strlen( i8* %to ) nounwind readonly > ; <i64> [#uses=1] > %tmp18 = tail call i64 @strlen( i8* %from ) nounwind
2008 Feb 16
2
[LLVMdev] linux/x86-64 codegen support
PR1711 is an x86 codegen problem that is blocking adoption of llvm-gcc by people using linux on x86-64 boxes. Could someone with access to one of these boxes take a look? I'll help try to debug this, but I don't have access to a machine. I bet it's a small tweak required in the x86 backend. Thanks! -Chris
2010 Nov 07
0
[LLVMdev] Hoisting elements of array argument into registers
David Peixotto <dmp <at> rice.edu> writes: > I am seeing the wf loop get optimized just fine with llvm 2.8 (and almost as good with head). I rechecked this and am I actually seeing the same results as you. I think I must have made a stupid mistake in my tests before - sorry for the noise. However, I found that we have a phase ordering problem which is preventing us getting as much
2007 Jul 03
4
[LLVMdev] Question about Constant Expressions
Chris, > We used to have a 'lowerconstantexpr' pass in transforms/scalar. I don't > know how to see deleted files in svn though. They should be "seen" in the certain revision, before they were deleted. -- With best regards, Anton Korobeynikov. Faculty of Mathematics & Mechanics, Saint Petersburg State University.
2010 Nov 06
2
[LLVMdev] Hoisting elements of array argument into registers
I am seeing the wf loop get optimized just fine with llvm 2.8 (and almost as good with head). I'm running on Mac OS X 10.6. I have an apple supplied llvm-gcc and a self compiled llvm 2.8. When I run $ llvm-gcc -emit-llvm -S M.c $ opt -O2 M.s | llvm-dis I see that: 1. Tail recursion has been eliminated from wf 2. The accesses to sp have been promoted to registers 3. The loop has
2008 Jan 12
1
[LLVMdev] Labels
I'm attempting to modify a parser generator to emit LLVM code instead of C. So far the experience has been trivial, but I am now running into an error regarding labels that I can't seem to solve. Situation 1: A label is used immediately after a void function call (l6 in this case): <snip> %tmp26 = load i32* @yybegin, align 4 %tmp27 = load i32* @yyend, align 4 call void
2008 Jun 11
4
[LLVMdev] Query on optimization and tail call.
Hi, While playing around on the LLVM, I tried this code: int sum(int n) { if (n == 0) return 0; else return n + sum(n-1); } and this is what "llvm-gcc -O2" gave me: define i32 @sum(i32 %n) nounwind { entry: %tmp215 = icmp eq i32 %n, 0 ; <i1> [#uses=1] br i1 %tmp215, label %bb10, label %tailrecurse.bb10_crit_edge tailrecurse.bb10_crit_edge: ; preds =
2008 Mar 04
0
[LLVMdev] Deleting Instructions after Intrinsic Creation
Hi, I tried creating intrinsics which are to be placeholders for a set of instructions which should not be executed by the backend. I want to retain only intrinsic,phi and terminator instructions in a basic block. I have taken care of the external dependencies of basic block. How do I delete the rest of the instructions? Thank You Aditya P.S: