[Target] move reciprocal estimate settings from TargetOptions to TargetLowering

The motivation for the change is that we can't have pseudo-global settings for
codegen living in TargetOptions because that doesn't work with LTO.

Ideally, these reciprocal attributes will be moved to the instruction-level via
FMF, metadata, or something else. But making them function attributes is at least
an improvement over the current state.

The ingredients of this patch are:

    Remove the reciprocal estimate command-line debug option.
    Add TargetRecip to TargetLowering.
    Remove TargetRecip from TargetOptions.
    Clean up the TargetRecip implementation to work with this new scheme.
    Set the default reciprocal settings in TargetLoweringBase (everything is off).
    Update the PowerPC defaults, users, and tests.
    Update the x86 defaults, users, and tests.

Note that if this patch needs to be reverted, the related clang patch checked in
at r283251 should be reverted too.

Differential Revision: https://reviews.llvm.org/D24816



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@283252 91177308-0d34-0410-b5e6-96231b3b80d8

1 files changed, 31 insertions, 15 deletions

diff --git a/test/CodeGen/PowerPC/recipest.ll b/test/CodeGen/PowerPC/recipest.ll
index c49660fdc3a..3a8e2ff7d61 100644
--- a/test/CodeGen/PowerPC/recipest.ll
+++ b/test/CodeGen/PowerPC/recipest.ll
@@ -1,6 +1,6 @@
 ; RUN: llc -verify-machineinstrs < %s -mtriple=powerpc64-unknown-linux-gnu -mcpu=pwr7 -enable-unsafe-fp-math -mattr=-vsx | FileCheck %s
-; RUN: llc -verify-machineinstrs < %s -mtriple=powerpc64-unknown-linux-gnu -mcpu=pwr7 -enable-unsafe-fp-math -mattr=-vsx -recip=sqrtf:0,sqrtd:0 | FileCheck %s -check-prefix=CHECK-NONR
 ; RUN: llc -verify-machineinstrs < %s -mtriple=powerpc64-unknown-linux-gnu -mcpu=pwr7 -mattr=-vsx | FileCheck -check-prefix=CHECK-SAFE %s
+
 target datalayout = "E-p:64:64:64-i1:8:8-i8:8:8-i16:16:16-i32:32:32-i64:64:64-f32:32:32-f64:64:64-f128:128:128-v128:128:128-n32:64"
 target triple = "powerpc64-unknown-linux-gnu"
 
@@ -25,19 +25,26 @@ define double @foo(double %a, double %b) nounwind {
 ; CHECK-NEXT: fmul
 ; CHECK: blr
 
-; CHECK-NONR: @foo
-; CHECK-NONR: frsqrte
-; CHECK-NONR-NOT: fmadd
-; CHECK-NONR: fmul
-; CHECK-NONR-NOT: fmadd
-; CHECK-NONR: blr
-
 ; CHECK-SAFE: @foo
 ; CHECK-SAFE: fsqrt
 ; CHECK-SAFE: fdiv
 ; CHECK-SAFE: blr
 }
 
+define double @no_estimate_refinement_f64(double %a, double %b) #0 {
+  %x = call double @llvm.sqrt.f64(double %b)
+  %r = fdiv double %a, %x
+  ret double %r
+
+; CHECK-LABEL: @no_estimate_refinement_f64
+; CHECK: frsqrte
+; CHECK-NOT: fmadd
+; CHECK: fmul
+; CHECK-NOT: fmadd
+; CHECK: blr
+}
+
+
 define double @foof(double %a, float %b) nounwind {
   %x = call float @llvm.sqrt.f32(float %b)
   %y = fpext float %x to double
@@ -98,19 +105,26 @@ define float @goo(float %a, float %b) nounwind {
 ; CHECK-NEXT: fmuls
 ; CHECK-NEXT: blr
 
-; CHECK-NONR: @goo
-; CHECK-NONR: frsqrtes
-; CHECK-NONR-NOT: fmadds
-; CHECK-NONR: fmuls
-; CHECK-NONR-NOT: fmadds
-; CHECK-NONR: blr
-
 ; CHECK-SAFE: @goo
 ; CHECK-SAFE: fsqrts
 ; CHECK-SAFE: fdivs
 ; CHECK-SAFE: blr
 }
 
+
+define float @no_estimate_refinement_f32(float %a, float %b) #0 {
+  %x = call float @llvm.sqrt.f32(float %b)
+  %r = fdiv float %a, %x
+  ret float %r
+
+; CHECK-LABEL: @no_estimate_refinement_f32
+; CHECK: frsqrtes
+; CHECK-NOT: fmadds
+; CHECK: fmuls
+; CHECK-NOT: fmadds
+; CHECK: blr
+}
+
 ; Recognize that this is rsqrt(a) * rcp(b) * c, 
 ; not 1 / ( 1 / sqrt(a)) * rcp(b) * c.
 define float @rsqrt_fmul(float %a, float %b, float %c) {
@@ -252,3 +266,5 @@ define <4 x float> @hoo3(<4 x float> %a) nounwind {
 ; CHECK-SAFE: blr
 }
 
+attributes #0 = { nounwind "reciprocal-estimates"="sqrtf:0,sqrtd:0" }
+