llvm-6502/test/Transforms/InstCombine/cast-sext-zext.ll

; RUN: llvm-as < %s | opt -instcombine | llvm-dis | not grep sext
; XFAIL: *

define zeroext i16 @t(i8 zeroext %on_off, i16* nocapture %puls) nounwind readonly {
entry:
	%0 = zext i8 %on_off to i32
	%1 = add i32 %0, -1
	%2 = sext i32 %1 to i64
	%3 = getelementptr i16* %puls, i64 %2
	%4 = load i16* %3, align 2
	ret i16 %4
}
- Teach CanEvaluateInDifferentType of this xform: sext (zext ty1), ty2 -> zext ty2 - Looking at the number of sign bits of the a sext instruction to determine whether new trunc + sext pair should be added when its source is being evaluated in a different type. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@62263 91177308-0d34-0410-b5e6-96231b3b80d8 2009-01-15 17:01:23 +00:00			`; RUN: llvm-as < %s \| opt -instcombine \| llvm-dis \| not grep sext`
Fix PR3452 (an infinite loop bootstrapping) by disabling the recent improvements to the EvaluateInDifferentType code. This code works by just inserted a bunch of new code and then seeing if it is useful. Instcombine is not allowed to do this: it can only insert new code if it is useful, and only when it is converging to a more canonical fixed point. Now that we iterate when DCE makes progress, this causes an infinite loop when the code ends up not being used. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@63483 91177308-0d34-0410-b5e6-96231b3b80d8 2009-01-31 19:05:27 +00:00			`; XFAIL: *`
- Teach CanEvaluateInDifferentType of this xform: sext (zext ty1), ty2 -> zext ty2 - Looking at the number of sign bits of the a sext instruction to determine whether new trunc + sext pair should be added when its source is being evaluated in a different type. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@62263 91177308-0d34-0410-b5e6-96231b3b80d8 2009-01-15 17:01:23 +00:00
			`define zeroext i16 @t(i8 zeroext %on_off, i16* nocapture %puls) nounwind readonly {`
			`entry:`
			`%0 = zext i8 %on_off to i32`
			`%1 = add i32 %0, -1`
			`%2 = sext i32 %1 to i64`
			`%3 = getelementptr i16* %puls, i64 %2`
			`%4 = load i16* %3, align 2`
			`ret i16 %4`
			`}`