[llvm-commits] [llvm] r91228 - /llvm/trunk/lib/Target/README.txt

[Eli Friedman]

Author: efriedma
Date: Sat Dec 12 15:41:48 2009
New Revision: 91228

URL: http://llvm.org/viewvc/llvm-project?rev=91228&view=rev
Log:
Remove some stuff that's already implemented.  Also, remove the note about
merging x >u 5 and x <s 20 because it's impossible to implement.


Modified:
    llvm/trunk/lib/Target/README.txt

Modified: llvm/trunk/lib/Target/README.txt
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Target/README.txt?rev=91228&r1=91227&r2=91228&view=diff

==============================================================================
--- llvm/trunk/lib/Target/README.txt (original)
+++ llvm/trunk/lib/Target/README.txt Sat Dec 12 15:41:48 2009
@@ -823,20 +823,6 @@
 
 //===---------------------------------------------------------------------===//
 
-Instcombine will merge comparisons like (x >= 10) && (x < 20) by producing (x -
-10) u< 10, but only when the comparisons have matching sign.
-
-This could be converted with a similiar technique. (PR1941)
-
-define i1 @test(i8 %x) {
-  %A = icmp uge i8 %x, 5
-  %B = icmp slt i8 %x, 20
-  %C = and i1 %A, %B
-  ret i1 %C
-}
-
-//===---------------------------------------------------------------------===//
-
 These functions perform the same computation, but produce different assembly.
 
 define i8 @select(i8 %x) readnone nounwind {
@@ -884,18 +870,6 @@
 
 //===---------------------------------------------------------------------===//
 
-From GCC Bug 15241:
-unsigned int
-foo (unsigned int a, unsigned int b)
-{
- if (a <= 7 && b <= 7)
-   baz ();
-}
-Should combine to "(a|b) <= 7".  Currently not optimized with "clang
--emit-llvm-bc | opt -std-compile-opts".
-
-//===---------------------------------------------------------------------===//
-
 From GCC Bug 3756:
 int
 pn (int n)
@@ -907,19 +881,6 @@
 
 //===---------------------------------------------------------------------===//
 
-From GCC Bug 28685:
-int test(int a, int b)
-{
- int lt = a < b;
- int eq = a == b;
-
- return (lt || eq);
-}
-Should combine to "a <= b".  Currently not optimized with "clang
--emit-llvm-bc | opt -std-compile-opts | llc".
-
-//===---------------------------------------------------------------------===//
-
 void a(int variable)
 {
  if (variable == 4 || variable == 6)
@@ -993,12 +954,6 @@
 
 //===---------------------------------------------------------------------===//
 
-int a(unsigned char* b) {return *b > 99;}
-There's an unnecessary zext in the generated code with "clang
--emit-llvm-bc | opt -std-compile-opts".
-
-//===---------------------------------------------------------------------===//
-
 int a(unsigned b) {return ((b << 31) | (b << 30)) >> 31;}
 Should be combined to  "((b >> 1) | b) & 1".  Currently not optimized
 with "clang -emit-llvm-bc | opt -std-compile-opts".
@@ -1011,12 +966,6 @@
 
 //===---------------------------------------------------------------------===//
 
-unsigned a(unsigned a) {return ((a | 1) & 3) | (a & -4);}
-Should combine to "a | 1".  Currently not optimized with "clang
--emit-llvm-bc | opt -std-compile-opts".
-
-//===---------------------------------------------------------------------===//
-
 int a(int a, int b, int c) {return (~a & c) | ((c|a) & b);}
 Should fold to "(~a & c) | (a & b)".  Currently not optimized with
 "clang -emit-llvm-bc | opt -std-compile-opts".