llvm-6502/test/Transforms/InstCombine/add-sitofp.ll

; RUN: opt < %s -instcombine -S | grep "add nuw nsw i32"

define double @x(i32 %a, i32 %b) nounwind {
  %m = lshr i32 %a, 24
  %n = and i32 %m, %b
  %o = sitofp i32 %n to double
  %p = fadd double %o, 1.0
  ret double %p
}
[InstCombine] mark ADD with nuw if no unsigned overflow Summary: As a starting step, we only use one simple heuristic: if the sign bits of both a and b are zero, we can prove "add a, b" do not unsigned overflow, and thus convert it to "add nuw a, b". Updated all affected tests and added two new tests (@zero_sign_bit and @zero_sign_bit2) in AddOverflow.ll Test Plan: make check-all Reviewers: eliben, rafael, meheff, chandlerc Reviewed By: chandlerc Subscribers: chandlerc, llvm-commits Differential Revision: http://reviews.llvm.org/D4144 git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@211084 91177308-0d34-0410-b5e6-96231b3b80d8 2014-06-17 00:42:07 +00:00			`; RUN: opt < %s -instcombine -S \| grep "add nuw nsw i32"`
Generalize the new code in instcombine's ComputeNumSignBits for handling and/or to handle more cases (such as this add-sitofp.ll testcase), and port it to selectiondag's ComputeNumSignBits. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@51469 91177308-0d34-0410-b5e6-96231b3b80d8 2008-05-23 02:28:01 +00:00
			`define double @x(i32 %a, i32 %b) nounwind {`
			`%m = lshr i32 %a, 24`
			`%n = and i32 %m, %b`
			`%o = sitofp i32 %n to double`
Split the Add, Sub, and Mul instruction opcodes into separate integer and floating-point opcodes, introducing FAdd, FSub, and FMul. For now, the AsmParser, BitcodeReader, and IRBuilder all preserve backwards compatability, and the Core LLVM APIs preserve backwards compatibility for IR producers. Most front-ends won't need to change immediately. This implements the first step of the plan outlined here: http://nondot.org/sabre/LLVMNotes/IntegerOverflow.txt git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@72897 91177308-0d34-0410-b5e6-96231b3b80d8 2009-06-04 22:49:04 +00:00			`%p = fadd double %o, 1.0`
Generalize the new code in instcombine's ComputeNumSignBits for handling and/or to handle more cases (such as this add-sitofp.ll testcase), and port it to selectiondag's ComputeNumSignBits. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@51469 91177308-0d34-0410-b5e6-96231b3b80d8 2008-05-23 02:28:01 +00:00			`ret double %p`
			`}`