shylie/llvm-project
1
0
Fork 0
Code Issues Pull Requests Actions Packages Projects Releases Wiki Activity
llvm-project/llvm/test/Transforms/LoopVectorize/select-cmp.ll
David Sherwood 26b7d9d622 [LoopVectorize] Permit vectorisation of more select(cmp(), X, Y) reduction patterns 
This patch adds further support for vectorisation of loops that involve
selecting an integer value based on a previous comparison. Consider the
following C++ loop:

  int r = a;
  for (int i = 0; i < n; i++) {
    if (src[i] > 3) {
      r = b;
    }
    src[i] += 2;
  }

We should be able to vectorise this loop because all we are doing is
selecting between two states - 'a' and 'b' - both of which are loop
invariant. This just involves building a vector of values that contain
either 'a' or 'b', where the final reduced value will be 'b' if any lane
contains 'b'.

The IR generated by clang typically looks like this:

  %phi = phi i32 [ %a, %entry ], [ %phi.update, %for.body ]
  ...
  %pred = icmp ugt i32 %val, i32 3
  %phi.update = select i1 %pred, i32 %b, i32 %phi

We already detect min/max patterns, which also involve a select + cmp.
However, with the min/max patterns we are selecting loaded values (and
hence loop variant) in the loop. In addition we only support certain
cmp predicates. This patch adds a new pattern matching function
(isSelectCmpPattern) and new RecurKind enums - SelectICmp & SelectFCmp.
We only support selecting values that are integer and loop invariant,
however we can support any kind of compare - integer or float.

Tests have been added here:

  Transforms/LoopVectorize/AArch64/sve-select-cmp.ll
  Transforms/LoopVectorize/select-cmp-predicated.ll
  Transforms/LoopVectorize/select-cmp.ll

Differential Revision: https://reviews.llvm.org/D108136
2021-10-11 09:41:38 +01:00

346 lines
17 KiB
LLVM
Raw Blame History

; RUN: opt -loop-vectorize -force-vector-interleave=1 -force-vector-width=4 -S < %s | FileCheck %s --check-prefix=CHECK-VF4IC1 --check-prefix=CHECK
; RUN: opt -loop-vectorize -force-vector-interleave=4 -force-vector-width=4 -S < %s | FileCheck %s --check-prefix=CHECK-VF4IC4 --check-prefix=CHECK
; RUN: opt -loop-vectorize -force-vector-interleave=4 -force-vector-width=1 -S < %s | FileCheck %s --check-prefix=CHECK-VF1IC4 --check-prefix=CHECK
define i32 @select_const_i32_from_icmp(i32* nocapture readonly %v, i64 %n) {
; CHECK-LABEL: @select_const_i32_from_icmp
; CHECK-VF4IC1: vector.body:
; CHECK-VF4IC1: [[VEC_PHI:%.*]] = phi <4 x i32> [ <i32 3, i32 3, i32 3, i32 3>, %vector.ph ], [ [[VEC_SEL:%.*]], %vector.body ]
; CHECK-VF4IC1: [[VEC_LOAD:%.*]] = load <4 x i32>
; CHECK-VF4IC1-NEXT: [[VEC_ICMP:%.*]] = icmp eq <4 x i32> [[VEC_LOAD]], <i32 3, i32 3, i32 3, i32 3>
; CHECK-VF4IC1-NEXT: [[VEC_SEL]] = select <4 x i1> [[VEC_ICMP]], <4 x i32> [[VEC_PHI]], <4 x i32> <i32 7, i32 7, i32 7, i32 7>
; CHECK-VF4IC1: middle.block:
; CHECK-VF4IC1-NEXT: [[FIN_ICMP:%.*]] = icmp ne <4 x i32> [[VEC_SEL]], <i32 3, i32 3, i32 3, i32 3>
; CHECK-VF4IC1-NEXT: [[OR_RDX:%.*]] = call i1 @llvm.vector.reduce.or.v4i1(<4 x i1> [[FIN_ICMP]])
; CHECK-VF4IC1-NEXT: {{.*}} = select i1 [[OR_RDX]], i32 7, i32 3
; CHECK-VF4IC4: vector.body:
; CHECK-VF4IC4: [[VEC_PHI1:%.*]] = phi <4 x i32> [ <i32 3, i32 3, i32 3, i32 3>, %vector.ph ], [ [[VEC_SEL1:%.*]], %vector.body ]
; CHECK-VF4IC4-NEXT: [[VEC_PHI2:%.*]] = phi <4 x i32> [ <i32 3, i32 3, i32 3, i32 3>, %vector.ph ], [ [[VEC_SEL2:%.*]], %vector.body ]
; CHECK-VF4IC4-NEXT: [[VEC_PHI3:%.*]] = phi <4 x i32> [ <i32 3, i32 3, i32 3, i32 3>, %vector.ph ], [ [[VEC_SEL3:%.*]], %vector.body ]
; CHECK-VF4IC4-NEXT: [[VEC_PHI4:%.*]] = phi <4 x i32> [ <i32 3, i32 3, i32 3, i32 3>, %vector.ph ], [ [[VEC_SEL4:%.*]], %vector.body ]
; CHECK-VF4IC4: [[VEC_ICMP1:%.*]] = icmp eq <4 x i32> {{.*}}, <i32 3, i32 3, i32 3, i32 3>
; CHECK-VF4IC4-NEXT: [[VEC_ICMP2:%.*]] = icmp eq <4 x i32> {{.*}}, <i32 3, i32 3, i32 3, i32 3>
; CHECK-VF4IC4-NEXT: [[VEC_ICMP3:%.*]] = icmp eq <4 x i32> {{.*}}, <i32 3, i32 3, i32 3, i32 3>
; CHECK-VF4IC4-NEXT: [[VEC_ICMP4:%.*]] = icmp eq <4 x i32> {{.*}}, <i32 3, i32 3, i32 3, i32 3>
; CHECK-VF4IC4-NEXT: [[VEC_SEL1:%.*]] = select <4 x i1> [[VEC_ICMP1]], <4 x i32> [[VEC_PHI1]], <4 x i32> <i32 7, i32 7, i32 7, i32 7>
; CHECK-VF4IC4-NEXT: [[VEC_SEL2:%.*]] = select <4 x i1> [[VEC_ICMP2]], <4 x i32> [[VEC_PHI2]], <4 x i32> <i32 7, i32 7, i32 7, i32 7>
; CHECK-VF4IC4-NEXT: [[VEC_SEL3:%.*]] = select <4 x i1> [[VEC_ICMP3]], <4 x i32> [[VEC_PHI3]], <4 x i32> <i32 7, i32 7, i32 7, i32 7>
; CHECK-VF4IC4-NEXT: [[VEC_SEL4:%.*]] = select <4 x i1> [[VEC_ICMP4]], <4 x i32> [[VEC_PHI4]], <4 x i32> <i32 7, i32 7, i32 7, i32 7>
; CHECK-VF4IC4: middle.block:
; CHECK-VF4IC4-NEXT: [[VEC_ICMP5:%.*]] = icmp ne <4 x i32> [[VEC_SEL1]], <i32 3, i32 3, i32 3, i32 3>
; CHECK-VF4IC4-NEXT: [[VEC_SEL5:%.*]] = select <4 x i1> [[VEC_ICMP5]], <4 x i32> [[VEC_SEL1]], <4 x i32> [[VEC_SEL2]]
; CHECK-VF4IC4-NEXT: [[VEC_ICMP6:%.*]] = icmp ne <4 x i32> [[VEC_SEL5]], <i32 3, i32 3, i32 3, i32 3>
; CHECK-VF4IC4-NEXT: [[VEC_SEL6:%.*]] = select <4 x i1> [[VEC_ICMP6]], <4 x i32> [[VEC_SEL5]], <4 x i32> [[VEC_SEL3]]
; CHECK-VF4IC4-NEXT: [[VEC_ICMP7:%.*]] = icmp ne <4 x i32> [[VEC_SEL6]], <i32 3, i32 3, i32 3, i32 3>
; CHECK-VF4IC4-NEXT: [[VEC_SEL_FIN:%.*]] = select <4 x i1> [[VEC_ICMP7]], <4 x i32> [[VEC_SEL6]], <4 x i32> [[VEC_SEL4]]
; CHECK-VF4IC4-NEXT: [[FIN_ICMP:%.*]] = icmp ne <4 x i32> [[VEC_SEL_FIN]], <i32 3, i32 3, i32 3, i32 3>
; CHECK-VF4IC4-NEXT: [[OR_RDX:%.*]] = call i1 @llvm.vector.reduce.or.v4i1(<4 x i1> [[FIN_ICMP]])
; CHECK-VF4IC4-NEXT: {{.*}} = select i1 [[OR_RDX]], i32 7, i32 3
; CHECK-VF1IC4: vector.body:
; CHECK-VF1IC4: [[VEC_PHI1:%.*]] = phi i32 [ 3, %vector.ph ], [ [[VEC_SEL1:%.*]], %vector.body ]
; CHECK-VF1IC4-NEXT: [[VEC_PHI2:%.*]] = phi i32 [ 3, %vector.ph ], [ [[VEC_SEL2:%.*]], %vector.body ]
; CHECK-VF1IC4-NEXT: [[VEC_PHI3:%.*]] = phi i32 [ 3, %vector.ph ], [ [[VEC_SEL3:%.*]], %vector.body ]
; CHECK-VF1IC4-NEXT: [[VEC_PHI4:%.*]] = phi i32 [ 3, %vector.ph ], [ [[VEC_SEL4:%.*]], %vector.body ]
; CHECK-VF1IC4: [[VEC_LOAD1:%.*]] = load i32
; CHECK-VF1IC4-NEXT: [[VEC_LOAD2:%.*]] = load i32
; CHECK-VF1IC4-NEXT: [[VEC_LOAD3:%.*]] = load i32
; CHECK-VF1IC4-NEXT: [[VEC_LOAD4:%.*]] = load i32
; CHECK-VF1IC4-NEXT: [[VEC_ICMP1:%.*]] = icmp eq i32 [[VEC_LOAD1]], 3
; CHECK-VF1IC4-NEXT: [[VEC_ICMP2:%.*]] = icmp eq i32 [[VEC_LOAD2]], 3
; CHECK-VF1IC4-NEXT: [[VEC_ICMP3:%.*]] = icmp eq i32 [[VEC_LOAD3]], 3
; CHECK-VF1IC4-NEXT: [[VEC_ICMP4:%.*]] = icmp eq i32 [[VEC_LOAD4]], 3
; CHECK-VF1IC4-NEXT: [[VEC_SEL1]] = select i1 [[VEC_ICMP1]], i32 [[VEC_PHI1]], i32 7
; CHECK-VF1IC4-NEXT: [[VEC_SEL2]] = select i1 [[VEC_ICMP2]], i32 [[VEC_PHI2]], i32 7
; CHECK-VF1IC4-NEXT: [[VEC_SEL3]] = select i1 [[VEC_ICMP3]], i32 [[VEC_PHI3]], i32 7
; CHECK-VF1IC4-NEXT: [[VEC_SEL4]] = select i1 [[VEC_ICMP4]], i32 [[VEC_PHI4]], i32 7
; CHECK-VF1IC4: middle.block:
; CHECK-VF1IC4-NEXT: [[VEC_ICMP4:%.*]] = icmp ne i32 [[VEC_SEL1]], 3
; CHECK-VF1IC4-NEXT: [[VEC_SEL5:%.*]] = select i1 [[VEC_ICMP4]], i32 [[VEC_SEL1]], i32 [[VEC_SEL2]]
; CHECK-VF1IC4-NEXT: [[VEC_ICMP5:%.*]] = icmp ne i32 [[VEC_SEL5]], 3
; CHECK-VF1IC4-NEXT: [[VEC_SEL6:%.*]] = select i1 [[VEC_ICMP5]], i32 [[VEC_SEL5]], i32 [[VEC_SEL3]]
; CHECK-VF1IC4-NEXT: [[VEC_ICMP6:%.*]] = icmp ne i32 [[VEC_SEL6]], 3
; CHECK-VF1IC4-NEXT: {{.*}} = select i1 [[VEC_ICMP6]], i32 [[VEC_SEL6]], i32 [[VEC_SEL4]]
entry:
br label %for.body
for.body: ; preds = %entry, %for.body
%0 = phi i64 [ 0, %entry ], [ %6, %for.body ]
%1 = phi i32 [ 3, %entry ], [ %5, %for.body ]
%2 = getelementptr inbounds i32, i32* %v, i64 %0
%3 = load i32, i32* %2, align 4
%4 = icmp eq i32 %3, 3
%5 = select i1 %4, i32 %1, i32 7
%6 = add nuw nsw i64 %0, 1
%7 = icmp eq i64 %6, %n
br i1 %7, label %exit, label %for.body
exit: ; preds = %for.body
ret i32 %5
}
define i32 @select_const_i32_from_icmp2(i32* nocapture readonly %v, i64 %n) {
; CHECK-LABEL: @select_const_i32_from_icmp2
; CHECK-VF4IC1: vector.body:
; CHECK-VF4IC1: [[VEC_PHI:%.*]] = phi <4 x i32> [ <i32 3, i32 3, i32 3, i32 3>, %vector.ph ], [ [[VEC_SEL:%.*]], %vector.body ]
; CHECK-VF4IC1: [[VEC_LOAD:%.*]] = load <4 x i32>
; CHECK-VF4IC1-NEXT: [[VEC_ICMP:%.*]] = icmp eq <4 x i32> [[VEC_LOAD]], <i32 3, i32 3, i32 3, i32 3>
; CHECK-VF4IC1-NEXT: [[VEC_SEL]] = select <4 x i1> [[VEC_ICMP]], <4 x i32> <i32 7, i32 7, i32 7, i32 7>, <4 x i32> [[VEC_PHI]]
; CHECK-VF4IC1: middle.block:
; CHECK-VF4IC1-NEXT: [[FIN_ICMP:%.*]] = icmp ne <4 x i32> [[VEC_SEL]], <i32 3, i32 3, i32 3, i32 3>
; CHECK-VF4IC1-NEXT: [[OR_RDX:%.*]] = call i1 @llvm.vector.reduce.or.v4i1(<4 x i1> [[FIN_ICMP]])
; CHECK-VF4IC1-NEXT: {{.*}} = select i1 [[OR_RDX]], i32 7, i32 3
entry:
br label %for.body
for.body: ; preds = %entry, %for.body
%0 = phi i64 [ 0, %entry ], [ %6, %for.body ]
%1 = phi i32 [ 3, %entry ], [ %5, %for.body ]
%2 = getelementptr inbounds i32, i32* %v, i64 %0
%3 = load i32, i32* %2, align 4
%4 = icmp eq i32 %3, 3
%5 = select i1 %4, i32 7, i32 %1
%6 = add nuw nsw i64 %0, 1
%7 = icmp eq i64 %6, %n
br i1 %7, label %exit, label %for.body
exit: ; preds = %for.body
ret i32 %5
}
define i32 @select_i32_from_icmp(i32* nocapture readonly %v, i32 %a, i32 %b, i64 %n) {
; CHECK-LABEL: @select_i32_from_icmp
; CHECK-VF4IC1: vector.ph:
; CHECK-VF4IC1: [[TMP1:%.*]] = insertelement <4 x i32> poison, i32 %a, i32 0
; CHECK-VF4IC1-NEXT: [[SPLAT_OF_A:%.*]] = shufflevector <4 x i32> [[TMP1]], <4 x i32> poison, <4 x i32> zeroinitializer
; CHECK-VF4IC1-NEXT: [[TMP2:%.*]] = insertelement <4 x i32> poison, i32 %b, i32 0
; CHECK-VF4IC1-NEXT: [[SPLAT_OF_B:%.*]] = shufflevector <4 x i32> [[TMP2]], <4 x i32> poison, <4 x i32> zeroinitializer
; CHECK-VF4IC1: vector.body:
; CHECK-VF4IC1: [[VEC_PHI:%.*]] = phi <4 x i32> [ [[SPLAT_OF_A]], %vector.ph ], [ [[VEC_SEL:%.*]], %vector.body ]
; CHECK-VF4IC1: [[VEC_LOAD:%.*]] = load <4 x i32>
; CHECK-VF4IC1-NEXT: [[VEC_ICMP:%.*]] = icmp eq <4 x i32> [[VEC_LOAD]], <i32 3, i32 3, i32 3, i32 3>
; CHECK-VF4IC1-NEXT: [[VEC_SEL]] = select <4 x i1> [[VEC_ICMP]], <4 x i32> [[VEC_PHI]], <4 x i32> [[SPLAT_OF_B]]
; CHECK-VF4IC1: middle.block:
; CHECK-VF4IC1-NEXT: [[FIN_INS:%.*]] = insertelement <4 x i32> poison, i32 %a, i32 0
; CHECK-VF4IC1-NEXT: [[FIN_SPLAT:%.*]] = shufflevector <4 x i32> [[FIN_INS]], <4 x i32> poison, <4 x i32> zeroinitializer
; CHECK-VF4IC1-NEXT: [[FIN_CMP:%.*]] = icmp ne <4 x i32> [[VEC_SEL]], [[FIN_SPLAT]]
; CHECK-VF4IC1-NEXT: [[OR_RDX:%.*]] = call i1 @llvm.vector.reduce.or.v4i1(<4 x i1> [[FIN_CMP]])
; CHECK-VF4IC1-NEXT: {{.*}} = select i1 [[OR_RDX]], i32 %b, i32 %a
entry:
br label %for.body
for.body: ; preds = %entry, %for.body
%0 = phi i64 [ 0, %entry ], [ %6, %for.body ]
%1 = phi i32 [ %a, %entry ], [ %5, %for.body ]
%2 = getelementptr inbounds i32, i32* %v, i64 %0
%3 = load i32, i32* %2, align 4
%4 = icmp eq i32 %3, 3
%5 = select i1 %4, i32 %1, i32 %b
%6 = add nuw nsw i64 %0, 1
%7 = icmp eq i64 %6, %n
br i1 %7, label %exit, label %for.body
exit: ; preds = %for.body
ret i32 %5
}
define i32 @select_const_i32_from_fcmp_fast(float* nocapture readonly %v, i64 %n) {
; CHECK-LABEL: @select_const_i32_from_fcmp_fast
; CHECK-VF4IC1: vector.body:
; CHECK-VF4IC1: [[VEC_PHI:%.*]] = phi <4 x i32> [ <i32 2, i32 2, i32 2, i32 2>, %vector.ph ], [ [[VEC_SEL:%.*]], %vector.body ]
; CHECK-VF4IC1: [[VEC_LOAD:%.*]] = load <4 x float>
; CHECK-VF4IC1-NEXT: [[VEC_FCMP:%.*]] = fcmp fast ueq <4 x float> [[VEC_LOAD]], <float 3.000000e+00, float 3.000000e+00, float 3.000000e+00, float 3.000000e+00>
; CHECK-VF4IC1-NEXT: [[VEC_SEL]] = select <4 x i1> [[VEC_FCMP]], <4 x i32> [[VEC_PHI]], <4 x i32> <i32 1, i32 1, i32 1, i32 1>
; CHECK-VF4IC1: middle.block:
; CHECK-VF4IC1-NEXT: [[FIN_ICMP:%.*]] = icmp ne <4 x i32> [[VEC_SEL]], <i32 2, i32 2, i32 2, i32 2>
; CHECK-VF4IC1-NEXT: [[OR_RDX:%.*]] = call i1 @llvm.vector.reduce.or.v4i1(<4 x i1> [[FIN_ICMP]])
; CHECK-VF4IC1-NEXT: {{.*}} = select i1 [[OR_RDX]], i32 1, i32 2
entry:
br label %for.body
for.body: ; preds = %entry, %for.body
%0 = phi i64 [ 0, %entry ], [ %6, %for.body ]
%1 = phi i32 [ 2, %entry ], [ %5, %for.body ]
%2 = getelementptr inbounds float, float* %v, i64 %0
%3 = load float, float* %2, align 4
%4 = fcmp fast ueq float %3, 3.0
%5 = select i1 %4, i32 %1, i32 1
%6 = add nuw nsw i64 %0, 1
%7 = icmp eq i64 %6, %n
br i1 %7, label %exit, label %for.body
exit: ; preds = %for.body
ret i32 %5
}
define i32 @select_const_i32_from_fcmp(float* nocapture readonly %v, i64 %n) {
; CHECK-LABEL: @select_const_i32_from_fcmp
; CHECK-VF4IC1: vector.body:
; CHECK-VF4IC1: [[VEC_PHI:%.*]] = phi <4 x i32> [ <i32 2, i32 2, i32 2, i32 2>, %vector.ph ], [ [[VEC_SEL:%.*]], %vector.body ]
; CHECK-VF4IC1: [[VEC_LOAD:%.*]] = load <4 x float>
; CHECK-VF4IC1-NEXT: [[VEC_FCMP:%.*]] = fcmp ueq <4 x float> [[VEC_LOAD]], <float 3.000000e+00, float 3.000000e+00, float 3.000000e+00, float 3.000000e+00>
; CHECK-VF4IC1-NEXT: [[VEC_SEL]] = select <4 x i1> [[VEC_FCMP]], <4 x i32> [[VEC_PHI]], <4 x i32> <i32 1, i32 1, i32 1, i32 1>
; CHECK-VF4IC1: middle.block:
; CHECK-VF4IC1-NEXT: [[FIN_ICMP:%.*]] = icmp ne <4 x i32> [[VEC_SEL]], <i32 2, i32 2, i32 2, i32 2>
; CHECK-VF4IC1-NEXT: [[OR_RDX:%.*]] = call i1 @llvm.vector.reduce.or.v4i1(<4 x i1> [[FIN_ICMP]])
; CHECK-VF4IC1-NEXT: {{.*}} = select i1 [[OR_RDX]], i32 1, i32 2
entry:
br label %for.body
for.body: ; preds = %entry, %for.body
%0 = phi i64 [ 0, %entry ], [ %6, %for.body ]
%1 = phi i32 [ 2, %entry ], [ %5, %for.body ]
%2 = getelementptr inbounds float, float* %v, i64 %0
%3 = load float, float* %2, align 4
%4 = fcmp ueq float %3, 3.0
%5 = select i1 %4, i32 %1, i32 1
%6 = add nuw nsw i64 %0, 1
%7 = icmp eq i64 %6, %n
br i1 %7, label %exit, label %for.body
exit: ; preds = %for.body
ret i32 %5
}
define i32 @select_i32_from_icmp_same_inputs(i32 %a, i32 %b, i64 %n) {
; CHECK-LABEL: @select_i32_from_icmp_same_inputs
; CHECK-VF4IC1: vector.ph:
; CHECK-VF4IC1: [[TMP1:%.*]] = insertelement <4 x i32> poison, i32 %a, i32 0
; CHECK-VF4IC1-NEXT: [[SPLAT_OF_A:%.*]] = shufflevector <4 x i32> [[TMP1]], <4 x i32> poison, <4 x i32> zeroinitializer
; CHECK-VF4IC1-NEXT: [[TMP2:%.*]] = insertelement <4 x i32> poison, i32 %b, i32 0
; CHECK-VF4IC1-NEXT: [[SPLAT_OF_B:%.*]] = shufflevector <4 x i32> [[TMP2]], <4 x i32> poison, <4 x i32> zeroinitializer
; CHECK-VF4IC1: vector.body:
; CHECK-VF4IC1: [[VEC_PHI:%.*]] = phi <4 x i32> [ [[SPLAT_OF_A]], %vector.ph ], [ [[VEC_SEL:%.*]], %vector.body ]
; CHECK-VF4IC1: [[VEC_ICMP:%.*]] = icmp eq <4 x i32> [[VEC_PHI]], <i32 3, i32 3, i32 3, i32 3>
; CHECK-VF4IC1-NEXT: [[VEC_SEL]] = select <4 x i1> [[VEC_ICMP]], <4 x i32> [[VEC_PHI]], <4 x i32> [[SPLAT_OF_B]]
; CHECK-VF4IC1: middle.block:
; CHECK-VF4IC1-NEXT: [[FIN_INS:%.*]] = insertelement <4 x i32> poison, i32 %a, i32 0
; CHECK-VF4IC1-NEXT: [[FIN_SPLAT:%.*]] = shufflevector <4 x i32> [[FIN_INS]], <4 x i32> poison, <4 x i32> zeroinitializer
; CHECK-VF4IC1-NEXT: [[FIN_CMP:%.*]] = icmp ne <4 x i32> [[VEC_SEL]], [[FIN_SPLAT]]
; CHECK-VF4IC1-NEXT: [[OR_RDX:%.*]] = call i1 @llvm.vector.reduce.or.v4i1(<4 x i1> [[FIN_CMP]])
; CHECK-VF4IC1-NEXT: {{.*}} = select i1 [[OR_RDX]], i32 %b, i32 %a
entry:
br label %for.body
for.body: ; preds = %entry, %for.body
%0 = phi i64 [ 0, %entry ], [ %4, %for.body ]
%1 = phi i32 [ %a, %entry ], [ %3, %for.body ]
%2 = icmp eq i32 %1, 3
%3 = select i1 %2, i32 %1, i32 %b
%4 = add nuw nsw i64 %0, 1
%5 = icmp eq i64 %4, %n
br i1 %5, label %exit, label %for.body
exit: ; preds = %for.body
ret i32 %3
}
; Negative tests
; We don't support FP reduction variables at the moment.
define float @select_const_f32_from_icmp(i32* nocapture readonly %v, i64 %n) {
; CHECK: @select_const_f32_from_icmp
; CHECK-NOT: vector.body
entry:
br label %for.body
for.body: ; preds = %entry, %for.body
%0 = phi i64 [ 0, %entry ], [ %6, %for.body ]
%1 = phi fast float [ 3.0, %entry ], [ %5, %for.body ]
%2 = getelementptr inbounds i32, i32* %v, i64 %0
%3 = load i32, i32* %2, align 4
%4 = icmp eq i32 %3, 3
%5 = select fast i1 %4, float %1, float 7.0
%6 = add nuw nsw i64 %0, 1
%7 = icmp eq i64 %6, %n
br i1 %7, label %exit, label %for.body
exit: ; preds = %for.body
ret float %5
}
; We don't support select/cmp reduction patterns where there is more than one
; use of the icmp/fcmp.
define i32 @select_const_i32_from_icmp_mul_use(i32* nocapture readonly %v1, i32* %v2, i64 %n) {
; CHECK-LABEL: @select_const_i32_from_icmp_mul_use
; CHECK-NOT: vector.body
entry:
br label %for.body
for.body: ; preds = %entry, %for.body
%0 = phi i64 [ 0, %entry ], [ %8, %for.body ]
%1 = phi i32 [ 3, %entry ], [ %6, %for.body ]
%2 = phi i32 [ 0, %entry ], [ %7, %for.body ]
%3 = getelementptr inbounds i32, i32* %v1, i64 %0
%4 = load i32, i32* %3, align 4
%5 = icmp eq i32 %4, 3
%6 = select i1 %5, i32 %1, i32 7
%7 = zext i1 %5 to i32
%8 = add nuw nsw i64 %0, 1
%9 = icmp eq i64 %8, %n
br i1 %9, label %exit, label %for.body
exit: ; preds = %for.body
store i32 %7, i32* %v2, align 4
ret i32 %6
}
; We don't support selecting loop-variant values.
define i32 @select_variant_i32_from_icmp(i32* nocapture readonly %v1, i32* nocapture readonly %v2, i64 %n) {
; CHECK-LABEL: @select_variant_i32_from_icmp
; CHECK-NOT: vector.body
entry:
br label %for.body
for.body: ; preds = %entry, %for.body
%0 = phi i64 [ 0, %entry ], [ %8, %for.body ]
%1 = phi i32 [ 3, %entry ], [ %7, %for.body ]
%2 = getelementptr inbounds i32, i32* %v1, i64 %0
%3 = load i32, i32* %2, align 4
%4 = getelementptr inbounds i32, i32* %v2, i64 %0
%5 = load i32, i32* %4, align 4
%6 = icmp eq i32 %3, 3
%7 = select i1 %6, i32 %1, i32 %5
%8 = add nuw nsw i64 %0, 1
%9 = icmp eq i64 %8, %n
br i1 %9, label %exit, label %for.body
exit: ; preds = %for.body
ret i32 %7
}
; We only support selects where the input comes from the same PHI as the
; reduction PHI. In the example below, the select uses the induction
; variable input and the icmp uses the reduction PHI.
define i32 @select_i32_from_icmp_non_redux_phi(i32 %a, i32 %b, i32 %n) {
; CHECK-LABEL: @select_i32_from_icmp_non_redux_phi
; CHECK-NOT: vector.body
entry:
br label %for.body
for.body: ; preds = %entry, %for.body
%0 = phi i32 [ 0, %entry ], [ %4, %for.body ]
%1 = phi i32 [ %a, %entry ], [ %3, %for.body ]
%2 = icmp eq i32 %1, 3
%3 = select i1 %2, i32 %0, i32 %b
%4 = add nuw nsw i32 %0, 1
%5 = icmp eq i32 %4, %n
br i1 %5, label %exit, label %for.body
exit: ; preds = %for.body
ret i32 %3
}
Reference in New Issue View Git Blame Copy Permalink