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7c65d4345e
Make use of the END. facility on all files > 1K so that we aren't wasting CPU cycles searching for RUN: lines that we'll never find. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@36059 91177308-0d34-0410-b5e6-96231b3b80d8
57 lines
1.3 KiB
LLVM
57 lines
1.3 KiB
LLVM
; If we have an 'and' of the result of an 'or', and one of the 'or' operands
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; cannot have contributed any of the resultant bits, delete the or. This
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; occurs for very common C/C++ code like this:
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;
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; struct foo { int A : 16; int B : 16; };
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; void test(struct foo *F, int X, int Y) {
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; F->A = X; F->B = Y;
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; }
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;
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; Which corresponds to test1.
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; RUN: llvm-upgrade < %s | llvm-as | opt -instcombine | llvm-dis | \
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; RUN: not grep {or }
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; END.
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int %test1(int %X, int %Y) {
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%A = and int %X, 7
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%B = and int %Y, 8
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%C = or int %A, %B
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%D = and int %C, 7 ;; This cannot include any bits from %Y!
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ret int %D
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}
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int %test2(int %X, ubyte %Y) {
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%B = cast ubyte %Y to int
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%C = or int %X, %B
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%D = and int %C, 65536 ;; This cannot include any bits from %Y!
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ret int %D
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}
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int %test3(int %X, int %Y) {
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%B = shl int %Y, ubyte 1
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%C = or int %X, %B
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%D = and int %C, 1 ;; This cannot include any bits from %Y!
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ret int %D
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}
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uint %test4(uint %X, uint %Y) {
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%B = shr uint %Y, ubyte 31
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%C = or uint %X, %B
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%D = and uint %C, 2 ;; This cannot include any bits from %Y!
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ret uint %D
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}
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int %or_test1(int %X, int %Y) {
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%A = and int %X, 1
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%B = or int %A, 1 ;; This cannot include any bits from X!
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ret int %B
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}
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ubyte %or_test2(ubyte %X, ubyte %Y) {
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%A = shl ubyte %X, ubyte 7
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%B = or ubyte %A, 128 ;; This cannot include any bits from X!
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ret ubyte %B
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}
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