llvm-6502/test/Transforms/InstCombine/2007-12-18-AddSelCmpSub.ll
Christopher Lamb 30f017ad89 Fold certain additions through selects (and their compares) so as to eliminate subtractions. This code is often produced by the SMAX expansion in SCEV.
This implements test/Transforms/InstCombine/2007-12-18-AddSelCmpSub.ll


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@45158 91177308-0d34-0410-b5e6-96231b3b80d8
2007-12-18 09:34:41 +00:00

38 lines
1.4 KiB
LLVM

; RUN: llvm-as < %s | opt -instcombine | llvm-dis | not grep {sub}
define i32 @foo(i32 %a) {
entry:
%tmp15 = sub i32 99, %a ; <i32> [#uses=2]
%tmp16 = icmp slt i32 %tmp15, 0 ; <i1> [#uses=1]
%smax = select i1 %tmp16, i32 0, i32 %tmp15 ; <i32> [#uses=1]
%tmp12 = add i32 %smax, %a ; <i32> [#uses=1]
%tmp13 = add i32 %tmp12, 1 ; <i32> [#uses=1]
ret i32 %tmp13
}
define i32 @bar(i32 %a) {
entry:
%tmp15 = sub i32 99, %a ; <i32> [#uses=2]
%tmp16 = icmp slt i32 %tmp15, 0 ; <i1> [#uses=1]
%smax = select i1 %tmp16, i32 0, i32 %tmp15 ; <i32> [#uses=1]
%tmp12 = add i32 %smax, %a ; <i32> [#uses=1]
ret i32 %tmp12
}
define i32 @baz(i32 %a) {
entry:
%tmp15 = sub i32 99, %a ; <i32> [#uses=1]
%tmp16 = icmp slt i32 %tmp15, 0 ; <i1> [#uses=1]
%smax = select i1 %tmp16, i32 0, i32 42 ; <i32> [#uses=1]
%tmp12 = add i32 %smax, %a ; <i32> [#uses=1]
ret i32 %tmp12
}
define i32 @fun(i32 %a) {
entry:
%tmp15 = sub i32 99, %a ; <i32> [#uses=1]
%tmp16 = icmp slt i32 %a, 0 ; <i1> [#uses=1]
%smax = select i1 %tmp16, i32 0, i32 %tmp15 ; <i32> [#uses=1]
%tmp12 = add i32 %smax, %a ; <i32> [#uses=1]
ret i32 %tmp12
}