[llvm] r225217 - [PowerPC] Remove old README.txt entry

Hal Finkel hfinkel at anl.gov
Mon Jan 5 14:20:23 PST 2015


Author: hfinkel
Date: Mon Jan  5 16:20:22 2015
New Revision: 225217

URL: http://llvm.org/viewvc/llvm-project?rev=225217&view=rev
Log:
[PowerPC] Remove old README.txt entry

We no longer generate horrible code for the stated function:

void f(signed char *a, _Bool b, _Bool c) {
  signed char t = 0;
  if (b)  t = *a;
  if (c)  *a = t;
}

for which we now generate:

.L.f:
        andi. 5, 5, 1
        cmpldi 1, 4, 0
        li 5, 0
        beq 1, .LBB0_2
        lbz 5, 0(3)
.LBB0_2:                                # %if.end
        bclr 4, 1, 0
        stb 5, 0(3)
        blr

so we don't need the README.txt entry.

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

Modified: llvm/trunk/lib/Target/PowerPC/README.txt
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Target/PowerPC/README.txt?rev=225217&r1=225216&r2=225217&view=diff
==============================================================================
--- llvm/trunk/lib/Target/PowerPC/README.txt (original)
+++ llvm/trunk/lib/Target/PowerPC/README.txt Mon Jan  5 16:20:22 2015
@@ -211,16 +211,6 @@ _foo:
 
 ===-------------------------------------------------------------------------===
 
-We generate really bad code for this:
-
-int f(signed char *a, _Bool b, _Bool c) {
-   signed char t = 0;
-  if (b)  t = *a;
-  if (c)  *a = t;
-}
-
-===-------------------------------------------------------------------------===
-
 On the G5, logical CR operations are more expensive in their three
 address form: ops that read/write the same register are half as expensive as
 those that read from two registers that are different from their destination.





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