llvm-6502/test/CodeGen/X86/2007-10-12-CoalesceExtSubReg.ll
Quentin Colombet a3fb49cd85 During SelectionDAG building explicitly set a node to constant zero when the
value is zero.
This allows optmizations to kick in more easily.
Fix some test cases so that they remain meaningful (i.e., not completely dead
coded) when optimizations apply.

<rdar://problem/14096009> superfluous multiply by high part of zero-extended
value.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@184222 91177308-0d34-0410-b5e6-96231b3b80d8
2013-06-18 20:14:39 +00:00

35 lines
1.3 KiB
LLVM

; RUN: llc < %s -march=x86 | not grep movb
define signext i16 @f(i32* %bp, i32* %ss) {
entry:
br label %cond_next127
cond_next127: ; preds = %cond_next391, %entry
%v.1 = phi i32 [ undef, %entry ], [ %tmp411, %cond_next391 ] ; <i32> [#uses=1]
%tmp149 = mul i32 0, %v.1 ; <i32> [#uses=0]
%tmpss = load i32* %ss, align 4 ; <i32> [#uses=1]
%tmpbp = load i32* %bp, align 4 ; <i32> [#uses=2]
%tmp254 = and i32 %tmpss, 15 ; <i32> [#uses=1]
%tmp256 = and i32 %tmpbp, 15 ; <i32> [#uses=2]
br label %cond_next391
cond_next391: ; preds = %cond_next127
%tmp393 = load i32* %ss, align 4 ; <i32> [#uses=1]
%tmp395 = load i32* %bp, align 4 ; <i32> [#uses=2]
%tmp396 = shl i32 %tmp393, %tmp395 ; <i32> [#uses=2]
%tmp398 = sub i32 32, %tmp256 ; <i32> [#uses=2]
%tmp399 = lshr i32 %tmp396, %tmp398 ; <i32> [#uses=1]
%tmp405 = lshr i32 %tmp396, 31 ; <i32> [#uses=1]
%tmp406 = add i32 %tmp405, -1 ; <i32> [#uses=1]
%tmp409 = lshr i32 %tmp406, %tmp398 ; <i32> [#uses=1]
%tmp411 = sub i32 %tmp399, %tmp409 ; <i32> [#uses=1]
%tmp422445 = add i32 %tmp254, 0 ; <i32> [#uses=1]
%tmp426447 = add i32 %tmp395, %tmp256 ; <i32> [#uses=1]
store i32 %tmp426447, i32* %bp, align 4
%tmp429448 = icmp ult i32 %tmp422445, 63 ; <i1> [#uses=1]
br i1 %tmp429448, label %cond_next127, label %UnifiedReturnBlock
UnifiedReturnBlock: ; preds = %cond_next391
ret i16 0
}