diff options
author | Dan Gohman <gohman@apple.com> | 2010-04-11 23:10:12 +0000 |
---|---|---|
committer | Dan Gohman <gohman@apple.com> | 2010-04-11 23:10:12 +0000 |
commit | 3fddbb337dd5d8de5317df62e8027a6dcd778e73 (patch) | |
tree | f934cbe83b98a92abb029521b8917bfc5a168264 /test/Transforms/IndVarSimplify/eliminate-comparison.ll | |
parent | 53c66eacc417c0113fba7159487b90005dc8f91e (diff) | |
download | external_llvm-3fddbb337dd5d8de5317df62e8027a6dcd778e73.zip external_llvm-3fddbb337dd5d8de5317df62e8027a6dcd778e73.tar.gz external_llvm-3fddbb337dd5d8de5317df62e8027a6dcd778e73.tar.bz2 |
Teach IndVarSimplify how to eliminate comparisons involving induction
variables. For example, with code like this:
for (i=0;i<n;++i)
if (i<n)
x[i] = 0;
IndVarSimplify will now recognize that i is always less than n inside
the loop, and eliminate the if.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@101000 91177308-0d34-0410-b5e6-96231b3b80d8
Diffstat (limited to 'test/Transforms/IndVarSimplify/eliminate-comparison.ll')
-rw-r--r-- | test/Transforms/IndVarSimplify/eliminate-comparison.ll | 40 |
1 files changed, 40 insertions, 0 deletions
diff --git a/test/Transforms/IndVarSimplify/eliminate-comparison.ll b/test/Transforms/IndVarSimplify/eliminate-comparison.ll new file mode 100644 index 0000000..d156974 --- /dev/null +++ b/test/Transforms/IndVarSimplify/eliminate-comparison.ll @@ -0,0 +1,40 @@ +; RUN: opt -indvars -S < %s | FileCheck %s + +; Indvars should be able to simplify simple comparisons involving +; induction variables. + +; CHECK: %cond = and i1 %tobool.not, true + +target datalayout = "e-p:64:64:64-i1:8:8-i8:8:8-i16:16:16-i32:32:32-i64:64:64-f32:32:32-f64:64:64-v64:64:64-v128:128:128-a0:0:64-s0:64:64-f80:128:128-n8:16:32:64" + +@X = external global [0 x double] + +define void @foo(i64 %n, i32* nocapture %p) nounwind { +entry: + %cmp9 = icmp sgt i64 %n, 0 + br i1 %cmp9, label %pre, label %return + +pre: + %t3 = load i32* %p + %tobool.not = icmp ne i32 %t3, 0 + br label %loop + +loop: + %i = phi i64 [ 0, %pre ], [ %inc, %for.inc ] + %cmp6 = icmp slt i64 %i, %n + %cond = and i1 %tobool.not, %cmp6 + br i1 %cond, label %if.then, label %for.inc + +if.then: + %arrayidx = getelementptr [0 x double]* @X, i64 0, i64 %i + store double 3.200000e+00, double* %arrayidx + br label %for.inc + +for.inc: + %inc = add nsw i64 %i, 1 + %exitcond = icmp sge i64 %inc, %n + br i1 %exitcond, label %return, label %loop + +return: + ret void +} |