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llvm-project/llvm/test/CodeGen/X86/peep-test-2.ll

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Rewrite some tests with FileCHeck in X86 codegen - Revise previous patches of the same purpose by fixing *) grep <PA> | not grep <PB> semantically is not the same as CHECK: <PA>{{^<PB>.*$}} as the former will check all occurrences of <PA> while the later only check the first match. As the result, CHECK needs putting in all place where <PA> occurs. *) grep <PA> | count <N> needs a final CHECK-NOT of the same pattern. (As 'CHECK-<N>' is proposed for discussion, converting 'grep | count <N>' where N > 1 is postponed.) llvm-svn: 180742
2013-04-30 06:41:29 +08:00
; RUN: llc < %s -march=x86 | FileCheck %s
; CHECK: testl
Arithmetic instructions don't set EFLAGS bits OF and CF bits the same say the "test" instruction does in overflow cases, so eliminating the test is only safe when those bits aren't needed, as is the case for COND_E and COND_NE, or if it can be proven that no overflow will occur. For now, just restrict the optimization to COND_E and COND_NE and don't do any overflow analysis. llvm-svn: 66318
2009-03-07 09:58:32 +08:00
; It's tempting to eliminate the testl instruction here and just use the
; EFLAGS value from the incl, however it can't be known whether the add
; will overflow, and if it does the incl would set OF, and the
; subsequent setg would return true.
target datalayout = "e-p:32:32:32-i1:8:8-i8:8:8-i16:16:16-i32:32:32-i64:32:64-f32:32:32-f64:32:64-v64:64:64-v128:128:128-a0:0:64-f80:128:128"
target triple = "i386-apple-darwin9.6"
define i32 @f(i32 %j) nounwind readnone {
entry:
%0 = add i32 %j, 1 ; <i32> [#uses=1]
%1 = icmp sgt i32 %0, 0 ; <i1> [#uses=1]
%2 = zext i1 %1 to i32 ; <i32> [#uses=1]
ret i32 %2
}