llvm-6502/test/Transforms/CodeGenPrepare/X86/extend-sink-hoist.ll
Manuel Jacob f8909fa140 CodeGenPrep: sink extends of illegal types into use block.
Summary:
This helps the instruction selector to lower an i64 * i64 -> i128
multiplication into a single instruction on targets which support it.

This is an update of D2973 which was reverted because of a bug reported
as PR19084.

Reviewers: t.p.northover, chapuni

Reviewed By: t.p.northover

CC: llvm-commits, alex, chapuni

Differential Revision: http://llvm-reviews.chandlerc.com/D3021

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@203797 91177308-0d34-0410-b5e6-96231b3b80d8
2014-03-13 13:36:25 +00:00

65 lines
1.5 KiB
LLVM

; RUN: opt -codegenprepare -disable-cgp-branch-opts -S < %s | FileCheck %s
target datalayout = "e-m:e-i64:64-f80:128-n8:16:32:64-S128"
target triple = "x86_64-unknown-linux-gnu"
; The first cast should be sunk into block2, in order that the
; instruction selector can form an efficient
; i64 * i64 -> i128 multiplication.
define i128 @sink(i64* %mem1, i64* %mem2) {
; CHECK-LABEL: block1:
; CHECK-NEXT: load
block1:
%l1 = load i64* %mem1
%s1 = sext i64 %l1 to i128
br label %block2
; CHECK-LABEL: block2:
; CHECK-NEXT: sext
; CHECK-NEXT: load
; CHECK-NEXT: sext
block2:
%l2 = load i64* %mem2
%s2 = sext i64 %l2 to i128
%res = mul i128 %s1, %s2
ret i128 %res
}
; The first cast should be hoisted into block1, in order that the
; instruction selector can form an extend-load.
define i64 @hoist(i32* %mem1, i32* %mem2) {
; CHECK-LABEL: block1:
; CHECK-NEXT: load
; CHECK-NEXT: sext
block1:
%l1 = load i32* %mem1
br label %block2
; CHECK-LABEL: block2:
; CHECK-NEXT: load
; CHECK-NEXT: sext
block2:
%s1 = sext i32 %l1 to i64
%l2 = load i32* %mem2
%s2 = sext i32 %l2 to i64
%res = mul i64 %s1, %s2
ret i64 %res
}
; Make sure the cast sink logic and OptimizeExtUses don't end up in an infinite
; loop.
define i128 @use_ext_source() {
block1:
%v1 = or i64 undef, undef
%v2 = zext i64 %v1 to i128
br i1 undef, label %block2, label %block3
block2:
%v3 = add i64 %v1, 1
%v4 = zext i64 %v3 to i128
br label %block3
block3:
%res = phi i128 [ %v2, %block1 ], [ %v4, %block2 ]
ret i128 %res
}