shl-scalar-widening.ll
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; NOTE: Assertions have been autogenerated by utils/update_llc_test_checks.py
; RUN: llc -mtriple=x86_64-linux-gnu -global-isel -verify-machineinstrs < %s -o - | FileCheck %s --check-prefix=X64
define i16 @test_shl_i4(i16 %v, i16 %a, i16 %b) {
; Let's say the arguments are the following unsigned
; integers in two’s complement representation:
;
; %v: 77 (0000 0000 0100 1101)
; %a: 74 (0000 0000 0100 1010)
; %b: 72 (0000 0000 0100 1000)
; X64-LABEL: test_shl_i4:
; X64: # %bb.0:
; X64-NEXT: # kill: def $esi killed $esi def $rsi
; X64-NEXT: # kill: def $edx killed $edx def $rdx
; X64-NEXT: leal (%rdx,%rsi), %ecx
; X64-NEXT: andb $15, %cl
; X64-NEXT: # kill: def $cl killed $cl killed $ecx
; X64-NEXT: shlb %cl, %dil
; X64-NEXT: movzbl %dil, %eax
; X64-NEXT: andw $15, %ax
; X64-NEXT: # kill: def $ax killed $ax killed $eax
; X64-NEXT: retq
%v.t = trunc i16 %v to i4 ; %v.t: 13 (1101)
%a.t = trunc i16 %a to i4 ; %a.t: 10 (1010)
%b.t = trunc i16 %b to i4 ; %b.t: 8 (1000)
%n.t = add i4 %a.t, %b.t ; %n.t: 2 (0010)
%r.t = shl i4 %v.t, %n.t ; %r.t: 4 (0100)
%r = zext i4 %r.t to i16
; %r: 4 (0000 0000 0000 0100)
ret i16 %r
; %di: 77 (0000 0000 0100 1101)
; %si: 74 (0000 0000 0100 1010)
; %dx: 72 (0000 0000 0100 1000)
; %dx: 146 (0000 0000 1001 0010)
; %dx: 2 (0000 0000 0000 0010)
; %cx: 2 (0000 0000 0000 0010)
; %di: 52 (0000 0000 0011 0100)
; %di: 4 (0000 0000 0000 0100)
; %ax: 4 (0000 0000 0000 0100)
; Let's pretend that legalizing G_SHL by widening its second
; source operand is done via G_ANYEXT rather than G_ZEXT and
; see what happens:
; addb %sil, %dl
; %dx: 146 (0000 0000 1001 0010)
; movl %edx, %ecx
; %cx: 146 (0000 0000 1001 0010)
; shlb %cl, %dil
; %di: 0 (0000 0000 0000 0000)
; andw $15, %di
; %di: 0 (0000 0000 0000 0000)
; movl %edi, %eax
; %ax: 0 (0000 0000 0000 0000)
; retq
}