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| author | Bill Wendling <isanbard@gmail.com> | 2012-03-10 17:56:03 +0000 |
|---|---|---|
| committer | Bill Wendling <isanbard@gmail.com> | 2012-03-10 17:56:03 +0000 |
| commit | 0624d2a1ecc2c0e3b17076cde1ed9781700d8c72 (patch) | |
| tree | b422b0c2a2fd9fb33ef88695b6f13b85a4e36b1c /llvm/test | |
| parent | b52221e941474cdb9fe25808e1936601342ba6fc (diff) | |
| download | bcm5719-llvm-0624d2a1ecc2c0e3b17076cde1ed9781700d8c72.tar.gz bcm5719-llvm-0624d2a1ecc2c0e3b17076cde1ed9781700d8c72.zip | |
Make this transformation slightly less agressive and more correct.
The 'CmpInst::isFalseWhenEqual' function returns 'false' for values other than
simply equality. For instance, it returns 'false' for <= or >=. This isn't the
correct behavior for this transformation, which is checking for strict equality
and non-equality. It was causing the gcc.c-torture/execute/frame-address.c test
to fail because it would completely (and incorrectly) optimize a whole function
into a 'ret i32 0'.
llvm-svn: 152497
Diffstat (limited to 'llvm/test')
| -rw-r--r-- | llvm/test/Transforms/InstCombine/2012-03-10-InstCombine.ll | 35 |
1 files changed, 35 insertions, 0 deletions
diff --git a/llvm/test/Transforms/InstCombine/2012-03-10-InstCombine.ll b/llvm/test/Transforms/InstCombine/2012-03-10-InstCombine.ll new file mode 100644 index 00000000000..68989972549 --- /dev/null +++ b/llvm/test/Transforms/InstCombine/2012-03-10-InstCombine.ll @@ -0,0 +1,35 @@ +; RUN: opt < %s -instcombine | FileCheck %s + +; Derived from gcc.c-torture/execute/frame-address.c + +; CHECK: @func +; CHECK: return: +; CHECK-NOT: ret i32 0 +; CHECK: ret i32 %retval + +define i32 @func(i8* %c, i8* %f) nounwind uwtable readnone noinline ssp { +entry: + %d = alloca i8, align 1 + store i8 0, i8* %d, align 1 + %cmp = icmp ugt i8* %d, %c + br i1 %cmp, label %if.else, label %if.then + +if.then: ; preds = %entry + %cmp2 = icmp ule i8* %d, %f + %not.cmp1 = icmp uge i8* %c, %f + %.cmp2 = and i1 %cmp2, %not.cmp1 + %land.ext = zext i1 %.cmp2 to i32 + br label %return + +if.else: ; preds = %entry + %cmp5 = icmp uge i8* %d, %f + %not.cmp3 = icmp ule i8* %c, %f + %.cmp5 = and i1 %cmp5, %not.cmp3 + %land.ext7 = zext i1 %.cmp5 to i32 + br label %return + +return: ; preds = %if.else, %if.then + %retval.0 = phi i32 [ %land.ext, %if.then ], [ %land.ext7, %if.else ] + ret i32 %retval.0 +} + |
