llvm/test/CodeGen/NVPTX/nvvm-reflect.ll
Justin Lebar 352f7fdadc [NVPTX] Let there be One True Way to set NVVMReflect params.
Summary:
Previously there were three ways to inform the NVVMReflect pass whether
you wanted to flush denormals to zero:

  * An LLVM command-line option
  * Parameters to the NVVMReflect constructor
  * Metadata on the module itself.

This change removes the first two, leaving only the third.

The motivation for this change, aside from simplifying things, is that
we want LLVM to be aware of whether it's operating in FTZ mode, so other
passes can use this information.  Ideally we'd have a target-generic
piece of metadata on the module.  This change moves us in that
direction.

Reviewers: tra

Subscribers: jholewinski, llvm-commits

Differential Revision: https://reviews.llvm.org/D28700

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@292068 91177308-0d34-0410-b5e6-96231b3b80d8
2017-01-15 16:54:35 +00:00

87 lines
2.8 KiB
LLVM

; We run nvvm-reflect (and then optimize) this module twice, once with metadata
; that enables FTZ, and again with metadata that disables it.
; RUN: cat %s > %t.noftz
; RUN: echo '!0 = !{i32 4, !"nvvm-reflect-ftz", i32 0}' >> %t.noftz
; RUN: opt %t.noftz -S -nvvm-reflect -O2 \
; RUN: | FileCheck %s --check-prefix=USE_FTZ_0 --check-prefix=CHECK
; RUN: cat %s > %t.ftz
; RUN: echo '!0 = !{i32 4, !"nvvm-reflect-ftz", i32 1}' >> %t.ftz
; RUN: opt %t.ftz -S -nvvm-reflect -O2 \
; RUN: | FileCheck %s --check-prefix=USE_FTZ_1 --check-prefix=CHECK
@str = private unnamed_addr addrspace(4) constant [11 x i8] c"__CUDA_FTZ\00"
declare i32 @__nvvm_reflect(i8*)
declare i8* @llvm.nvvm.ptr.constant.to.gen.p0i8.p4i8(i8 addrspace(4)*)
; CHECK-LABEL: @foo
define float @foo(float %a, float %b) {
; CHECK-NOT: call i32 @__nvvm_reflect
%ptr = tail call i8* @llvm.nvvm.ptr.constant.to.gen.p0i8.p4i8(i8 addrspace(4)* getelementptr inbounds ([11 x i8], [11 x i8] addrspace(4)* @str, i32 0, i32 0))
%reflect = tail call i32 @__nvvm_reflect(i8* %ptr)
%cmp = icmp ugt i32 %reflect, 0
br i1 %cmp, label %use_mul, label %use_add
use_mul:
; USE_FTZ_1: fmul float %a, %b
; USE_FTZ_0-NOT: fadd float %a, %b
%ret1 = fmul float %a, %b
br label %exit
use_add:
; USE_FTZ_0: fadd float %a, %b
; USE_FTZ_1-NOT: fmul float %a, %b
%ret2 = fadd float %a, %b
br label %exit
exit:
%ret = phi float [%ret1, %use_mul], [%ret2, %use_add]
ret float %ret
}
declare i32 @llvm.nvvm.reflect.p0i8(i8*)
; CHECK-LABEL: define i32 @intrinsic
define i32 @intrinsic() {
; CHECK-NOT: call i32 @llvm.nvvm.reflect
; USE_FTZ_0: ret i32 0
; USE_FTZ_1: ret i32 1
%ptr = tail call i8* @llvm.nvvm.ptr.constant.to.gen.p0i8.p4i8(i8 addrspace(4)* getelementptr inbounds ([11 x i8], [11 x i8] addrspace(4)* @str, i32 0, i32 0))
%reflect = tail call i32 @llvm.nvvm.reflect.p0i8(i8* %ptr)
ret i32 %reflect
}
; CUDA-7.0 passes __nvvm_reflect argument slightly differently.
; Verify that it works, too
@"$str" = private addrspace(1) constant [11 x i8] c"__CUDA_FTZ\00"
; CHECK-LABEL: @bar
define float @bar(float %a, float %b) {
; CHECK-NOT: call i32 @__nvvm_reflect
%reflect = call i32 @__nvvm_reflect(i8* addrspacecast (i8 addrspace(1)* getelementptr inbounds ([11 x i8], [11 x i8] addrspace(1)* @"$str", i32 0, i32 0) to i8*))
%cmp = icmp ne i32 %reflect, 0
br i1 %cmp, label %use_mul, label %use_add
use_mul:
; USE_FTZ_1: fmul float %a, %b
; USE_FTZ_0-NOT: fadd float %a, %b
%ret1 = fmul float %a, %b
br label %exit
use_add:
; USE_FTZ_0: fadd float %a, %b
; USE_FTZ_1-NOT: fmul float %a, %b
%ret2 = fadd float %a, %b
br label %exit
exit:
%ret = phi float [%ret1, %use_mul], [%ret2, %use_add]
ret float %ret
}
!llvm.module.flags = !{!0}
; A module flag is added to the end of this file by the RUN lines at the top.