1
0
mirror of https://github.com/RPCS3/llvm-mirror.git synced 2024-11-25 20:23:11 +01:00
llvm-mirror/test/Transforms/LoopStrengthReduce/2011-10-06-ReusePhi.ll
Jingyue Wu 8fd4d61a47 [LSR] canonicalize Prod*(1<<C) to Prod<<C
Summary:
Because LSR happens at a late stage where mul of a power of 2 is
typically canonicalized to shl, this canonicalization emits code that
can be better CSE'ed.

Test Plan:
Transforms/LoopStrengthReduce/shl.ll shows how this change makes GVN more
powerful. Fixes some existing tests due to this change.

Reviewers: sanjoy, majnemer, atrick

Reviewed By: majnemer, atrick

Subscribers: majnemer, llvm-commits

Differential Revision: http://reviews.llvm.org/D10448

llvm-svn: 240573
2015-06-24 19:28:40 +00:00

58 lines
2.0 KiB
LLVM

; RUN: opt -loop-reduce -S < %s | FileCheck %s
;
; Test LSR's intelligence regarding phi reuse.
; Verify that scaled GEPs are not reused. rdar://5064068
target triple = "x86-apple-darwin"
; Provide legal integer types.
target datalayout = "n8:16:32:64"
; CHECK-LABEL: @test(
; multiplies are hoisted out of the loop
; CHECK: while.body.lr.ph:
; CHECK: shl i64
; CHECK: shl i64
; GEPs are ugly
; CHECK: while.body:
; CHECK: phi
; CHECK: phi
; CHECK: phi
; CHECK: phi
; CHECK-NOT: phi
; CHECK: bitcast float* {{.*}} to i1*
; CHECK: bitcast float* {{.*}} to i1*
; CHECK: getelementptr i1, i1*
; CHECK: getelementptr i1, i1*
define float @test(float* nocapture %A, float* nocapture %B, i32 %N, i32 %IA, i32 %IB) nounwind uwtable readonly ssp {
entry:
%cmp1 = icmp sgt i32 %N, 0
br i1 %cmp1, label %while.body.lr.ph, label %while.end
while.body.lr.ph: ; preds = %entry
%idx.ext = sext i32 %IA to i64
%idx.ext2 = sext i32 %IB to i64
br label %while.body
while.body: ; preds = %while.body.lr.ph, %while.body
%A.addr.05 = phi float* [ %A, %while.body.lr.ph ], [ %add.ptr, %while.body ]
%B.addr.04 = phi float* [ %B, %while.body.lr.ph ], [ %add.ptr3, %while.body ]
%N.addr.03 = phi i32 [ %N, %while.body.lr.ph ], [ %sub, %while.body ]
%Sum0.02 = phi float [ 0.000000e+00, %while.body.lr.ph ], [ %add, %while.body ]
%0 = load float, float* %A.addr.05, align 4
%1 = load float, float* %B.addr.04, align 4
%mul = fmul float %0, %1
%add = fadd float %Sum0.02, %mul
%add.ptr = getelementptr inbounds float, float* %A.addr.05, i64 %idx.ext
%add.ptr3 = getelementptr inbounds float, float* %B.addr.04, i64 %idx.ext2
%sub = add nsw i32 %N.addr.03, -1
%cmp = icmp sgt i32 %sub, 0
br i1 %cmp, label %while.body, label %while.end
while.end: ; preds = %while.body, %entry
%Sum0.0.lcssa = phi float [ 0.000000e+00, %entry ], [ %add, %while.body ]
ret float %Sum0.0.lcssa
}