llvm-project/llvm/test/CodeGen/X86/ret-i64-0.ll

; RUN: llc < %s -mtriple=i686-- | grep xor | count 2

define i64 @foo() nounwind {
  ret i64 0
}
X86: Do not use llc -march in tests. `llc -march` is problematic because it only switches the target architecture, but leaves the operating system unchanged. This occasionally leads to indeterministic tests because the OS from LLVM_DEFAULT_TARGET_TRIPLE is used. However we can simply always use `llc -mtriple` instead. This changes all the tests to do this to avoid people using -march when they copy and paste parts of tests. See also the discussion in https://reviews.llvm.org/D35287 llvm-svn: 309774 2017-08-02 08:28:10 +08:00			`; RUN: llc < %s -mtriple=i686-- \| grep xor \| count 2`
When the coalescer is doing rematerializing, have it remove the copy instruction from the instruction list before asking the target to create the new instruction. This gets the old instruction out of the way so that it doesn't interfere with the target's rematerialization code. In the case of x86, this helps it find more cases where EFLAGS is not live. Also, in the X86InstrInfo.cpp, teach isSafeToClobberEFLAGS to check to see if it reached the end of the block after scanning each instruction, instead of just before. This lets it notice when the end of the block is only two instructions away, without doing any additional scanning. These changes allow rematerialization to clobber EFLAGS in more cases, for example using xor instead of mov to set the return value to zero in the included testcase. llvm-svn: 57872 2008-10-21 11:24:31 +08:00
remove some unneeded eh generation llvm-svn: 57887 2008-10-21 11:49:19 +08:00			`define i64 @foo() nounwind {`
When the coalescer is doing rematerializing, have it remove the copy instruction from the instruction list before asking the target to create the new instruction. This gets the old instruction out of the way so that it doesn't interfere with the target's rematerialization code. In the case of x86, this helps it find more cases where EFLAGS is not live. Also, in the X86InstrInfo.cpp, teach isSafeToClobberEFLAGS to check to see if it reached the end of the block after scanning each instruction, instead of just before. This lets it notice when the end of the block is only two instructions away, without doing any additional scanning. These changes allow rematerialization to clobber EFLAGS in more cases, for example using xor instead of mov to set the return value to zero in the included testcase. llvm-svn: 57872 2008-10-21 11:24:31 +08:00			`ret i64 0`
			`}`