mirror of
https://github.com/RPCS3/llvm-mirror.git
synced 2024-11-26 04:32:44 +01:00
822bc4e4d3
Increase threshold to unroll a loop which contains an "if" statement whose condition defined by a PHI belonging to the loop. This may help to eliminate if region and potentially even PHI itself, saving on both divergence and registers used for the PHI. Add a small bonus for each of such "if" statements. Differential Revision: https://reviews.llvm.org/D31693 llvm-svn: 299779
101 lines
2.8 KiB
LLVM
101 lines
2.8 KiB
LLVM
; RUN: opt -mtriple=amdgcn-- -loop-unroll -simplifycfg -sroa %s -S -o - | FileCheck %s
|
|
; RUN: opt -mtriple=r600-- -loop-unroll -simplifycfg -sroa %s -S -o - | FileCheck %s
|
|
|
|
|
|
; This test contains a simple loop that initializes an array declared in
|
|
; private memory. We want to make sure these kinds of loops are always
|
|
; unrolled, because private memory is slow.
|
|
|
|
; CHECK-LABEL: @private_memory
|
|
; CHECK-NOT: alloca
|
|
; CHECK: store i32 5, i32 addrspace(1)* %out
|
|
define amdgpu_kernel void @private_memory(i32 addrspace(1)* %out) {
|
|
entry:
|
|
%0 = alloca [32 x i32]
|
|
br label %loop.header
|
|
|
|
loop.header:
|
|
%counter = phi i32 [0, %entry], [%inc, %loop.inc]
|
|
br label %loop.body
|
|
|
|
loop.body:
|
|
%ptr = getelementptr [32 x i32], [32 x i32]* %0, i32 0, i32 %counter
|
|
store i32 %counter, i32* %ptr
|
|
br label %loop.inc
|
|
|
|
loop.inc:
|
|
%inc = add i32 %counter, 1
|
|
%1 = icmp sge i32 %counter, 32
|
|
br i1 %1, label %exit, label %loop.header
|
|
|
|
exit:
|
|
%2 = getelementptr [32 x i32], [32 x i32]* %0, i32 0, i32 5
|
|
%3 = load i32, i32* %2
|
|
store i32 %3, i32 addrspace(1)* %out
|
|
ret void
|
|
}
|
|
|
|
; Check that loop is unrolled for local memory references
|
|
|
|
; CHECK-LABEL: @local_memory
|
|
; CHECK: getelementptr i32, i32 addrspace(1)* %out, i32 128
|
|
; CHECK-NEXT: store
|
|
; CHECK-NEXT: ret
|
|
define amdgpu_kernel void @local_memory(i32 addrspace(1)* %out, i32 addrspace(3)* %lds) {
|
|
entry:
|
|
br label %loop.header
|
|
|
|
loop.header:
|
|
%counter = phi i32 [0, %entry], [%inc, %loop.inc]
|
|
br label %loop.body
|
|
|
|
loop.body:
|
|
%ptr_lds = getelementptr i32, i32 addrspace(3)* %lds, i32 %counter
|
|
%val = load i32, i32 addrspace(3)* %ptr_lds
|
|
%ptr_out = getelementptr i32, i32 addrspace(1)* %out, i32 %counter
|
|
store i32 %val, i32 addrspace(1)* %ptr_out
|
|
br label %loop.inc
|
|
|
|
loop.inc:
|
|
%inc = add i32 %counter, 1
|
|
%cond = icmp sge i32 %counter, 128
|
|
br i1 %cond, label %exit, label %loop.header
|
|
|
|
exit:
|
|
ret void
|
|
}
|
|
|
|
; Check that a loop with if inside completely unrolled to eliminate phi and if
|
|
|
|
; CHECK-LABEL: @unroll_for_if
|
|
; CHECK: entry:
|
|
; CHECK-NEXT: getelementptr
|
|
; CHECK-NEXT: store
|
|
; CHECK-NEXT: getelementptr
|
|
; CHECK-NEXT: store
|
|
; CHECK-NOT: br
|
|
define amdgpu_kernel void @unroll_for_if(i32* %a) {
|
|
entry:
|
|
br label %for.body
|
|
|
|
for.body: ; preds = %entry, %for.inc
|
|
%i1 = phi i32 [ 0, %entry ], [ %inc, %for.inc ]
|
|
%and = and i32 %i1, 1
|
|
%tobool = icmp eq i32 %and, 0
|
|
br i1 %tobool, label %for.inc, label %if.then
|
|
|
|
if.then: ; preds = %for.body
|
|
%0 = sext i32 %i1 to i64
|
|
%arrayidx = getelementptr inbounds i32, i32* %a, i64 %0
|
|
store i32 0, i32* %arrayidx, align 4
|
|
br label %for.inc
|
|
|
|
for.inc: ; preds = %for.body, %if.then
|
|
%inc = add nuw nsw i32 %i1, 1
|
|
%cmp = icmp ult i32 %inc, 48
|
|
br i1 %cmp, label %for.body, label %for.end
|
|
|
|
for.end: ; preds = %for.cond
|
|
ret void
|
|
}
|