[llvm] r362244 - [Tests] Add tests for loop predication of loops w/ne latch conditions
Philip Reames via llvm-commits
llvm-commits at lists.llvm.org
Fri May 31 09:54:39 PDT 2019
Author: reames
Date: Fri May 31 09:54:38 2019
New Revision: 362244
URL: http://llvm.org/viewvc/llvm-project?rev=362244&view=rev
Log:
[Tests] Add tests for loop predication of loops w/ne latch conditions
Modified:
llvm/trunk/test/Transforms/LoopPredication/basic.ll
Modified: llvm/trunk/test/Transforms/LoopPredication/basic.ll
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/Transforms/LoopPredication/basic.ll?rev=362244&r1=362243&r2=362244&view=diff
==============================================================================
--- llvm/trunk/test/Transforms/LoopPredication/basic.ll (original)
+++ llvm/trunk/test/Transforms/LoopPredication/basic.ll Fri May 31 09:54:38 2019
@@ -1595,3 +1595,175 @@ exit:
%result = phi i32 [ %loop.acc.next, %loop ]
ret i32 %result
}
+
+; NE Check (as produced by LFTR) where we can prove Start < End via simple
+; instruction analysis
+define i32 @ne_latch_zext(i32* %array, i32 %length, i16 %n16) {
+; CHECK-LABEL: @ne_latch_zext(
+; CHECK-NEXT: loop.preheader:
+; CHECK-NEXT: [[N:%.*]] = zext i16 [[N16:%.*]] to i32
+; CHECK-NEXT: br label [[LOOP:%.*]]
+; CHECK: loop:
+; CHECK-NEXT: [[I:%.*]] = phi i32 [ [[I_NEXT:%.*]], [[LOOP]] ], [ 0, [[LOOP_PREHEADER:%.*]] ]
+; CHECK-NEXT: [[WITHIN_BOUNDS:%.*]] = icmp ult i32 [[I]], [[LENGTH:%.*]]
+; CHECK-NEXT: call void (i1, ...) @llvm.experimental.guard(i1 [[WITHIN_BOUNDS]], i32 9) [ "deopt"() ]
+; CHECK-NEXT: [[I_NEXT]] = add nuw i32 [[I]], 1
+; CHECK-NEXT: [[CONTINUE:%.*]] = icmp ne i32 [[I_NEXT]], [[N]]
+; CHECK-NEXT: br i1 [[CONTINUE]], label [[LOOP]], label [[EXIT:%.*]]
+; CHECK: exit:
+; CHECK-NEXT: ret i32 0
+;
+loop.preheader:
+ %n = zext i16 %n16 to i32
+ br label %loop
+
+loop:
+ %i = phi i32 [ %i.next, %loop ], [ 0, %loop.preheader ]
+ %within.bounds = icmp ult i32 %i, %length
+ call void (i1, ...) @llvm.experimental.guard(i1 %within.bounds, i32 9) [ "deopt"() ]
+
+ %i.next = add nuw i32 %i, 1
+ %continue = icmp ne i32 %i.next, %n
+ br i1 %continue, label %loop, label %exit
+
+exit:
+ ret i32 0
+}
+
+; NE Check (as produced by LFTR) where we can prove Start < End via the
+; condition guarding the loop entry.
+define i32 @ne_latch_dom_check(i32* %array, i32 %length, i32 %n) {
+; CHECK-LABEL: @ne_latch_dom_check(
+; CHECK-NEXT: entry:
+; CHECK-NEXT: [[TMP5:%.*]] = icmp sle i32 [[N:%.*]], 0
+; CHECK-NEXT: br i1 [[TMP5]], label [[EXIT:%.*]], label [[LOOP_PREHEADER:%.*]]
+; CHECK: loop.preheader:
+; CHECK-NEXT: br label [[LOOP:%.*]]
+; CHECK: loop:
+; CHECK-NEXT: [[I:%.*]] = phi i32 [ [[I_NEXT:%.*]], [[LOOP]] ], [ 0, [[LOOP_PREHEADER]] ]
+; CHECK-NEXT: [[WITHIN_BOUNDS:%.*]] = icmp ult i32 [[I]], [[LENGTH:%.*]]
+; CHECK-NEXT: call void (i1, ...) @llvm.experimental.guard(i1 [[WITHIN_BOUNDS]], i32 9) [ "deopt"() ]
+; CHECK-NEXT: [[I_NEXT]] = add nuw i32 [[I]], 1
+; CHECK-NEXT: [[CONTINUE:%.*]] = icmp ne i32 [[I_NEXT]], [[N]]
+; CHECK-NEXT: br i1 [[CONTINUE]], label [[LOOP]], label [[EXIT_LOOPEXIT:%.*]]
+; CHECK: exit.loopexit:
+; CHECK-NEXT: br label [[EXIT]]
+; CHECK: exit:
+; CHECK-NEXT: ret i32 0
+;
+entry:
+ %tmp5 = icmp sle i32 %n, 0
+ br i1 %tmp5, label %exit, label %loop.preheader
+
+loop.preheader:
+ br label %loop
+
+loop:
+ %i = phi i32 [ %i.next, %loop ], [ 0, %loop.preheader ]
+ %within.bounds = icmp ult i32 %i, %length
+ call void (i1, ...) @llvm.experimental.guard(i1 %within.bounds, i32 9) [ "deopt"() ]
+
+ %i.next = add nuw i32 %i, 1
+ %continue = icmp ne i32 %i.next, %n
+ br i1 %continue, label %loop, label %exit
+
+exit:
+ ret i32 0
+}
+
+; NE latch - can't prove (end-start) mod step == 0 (i.e. might wrap
+; around several times or even be infinite)
+define i32 @neg_ne_latch_mod_step(i32* %array, i32 %length, i16 %n16) {
+; CHECK-LABEL: @neg_ne_latch_mod_step(
+; CHECK-NEXT: loop.preheader:
+; CHECK-NEXT: [[N:%.*]] = zext i16 [[N16:%.*]] to i32
+; CHECK-NEXT: br label [[LOOP:%.*]]
+; CHECK: loop:
+; CHECK-NEXT: [[I:%.*]] = phi i32 [ [[I_NEXT:%.*]], [[LOOP]] ], [ 0, [[LOOP_PREHEADER:%.*]] ]
+; CHECK-NEXT: [[WITHIN_BOUNDS:%.*]] = icmp ult i32 [[I]], [[LENGTH:%.*]]
+; CHECK-NEXT: call void (i1, ...) @llvm.experimental.guard(i1 [[WITHIN_BOUNDS]], i32 9) [ "deopt"() ]
+; CHECK-NEXT: [[I_NEXT]] = add i32 [[I]], 3
+; CHECK-NEXT: [[CONTINUE:%.*]] = icmp ne i32 [[I_NEXT]], [[N]]
+; CHECK-NEXT: br i1 [[CONTINUE]], label [[LOOP]], label [[EXIT:%.*]]
+; CHECK: exit:
+; CHECK-NEXT: ret i32 0
+;
+loop.preheader:
+ %n = zext i16 %n16 to i32
+ br label %loop
+
+loop:
+ %i = phi i32 [ %i.next, %loop ], [ 0, %loop.preheader ]
+ %within.bounds = icmp ult i32 %i, %length
+ call void (i1, ...) @llvm.experimental.guard(i1 %within.bounds, i32 9) [ "deopt"() ]
+
+ %i.next = add i32 %i, 3
+ %continue = icmp ne i32 %i.next, %n
+ br i1 %continue, label %loop, label %exit
+
+exit:
+ ret i32 0
+}
+
+; NE latch - TODO: could prove (end-start) mod step == 0
+define i32 @ne_latch_mod_step(i32* %array, i32 %length) {
+; CHECK-LABEL: @ne_latch_mod_step(
+; CHECK-NEXT: loop.preheader:
+; CHECK-NEXT: br label [[LOOP:%.*]]
+; CHECK: loop:
+; CHECK-NEXT: [[I:%.*]] = phi i32 [ [[I_NEXT:%.*]], [[LOOP]] ], [ 0, [[LOOP_PREHEADER:%.*]] ]
+; CHECK-NEXT: [[WITHIN_BOUNDS:%.*]] = icmp ult i32 [[I]], [[LENGTH:%.*]]
+; CHECK-NEXT: call void (i1, ...) @llvm.experimental.guard(i1 [[WITHIN_BOUNDS]], i32 9) [ "deopt"() ]
+; CHECK-NEXT: [[I_NEXT]] = add nuw i32 [[I]], 2
+; CHECK-NEXT: [[CONTINUE:%.*]] = icmp ne i32 [[I_NEXT]], 400
+; CHECK-NEXT: br i1 [[CONTINUE]], label [[LOOP]], label [[EXIT:%.*]]
+; CHECK: exit:
+; CHECK-NEXT: ret i32 0
+;
+loop.preheader:
+ br label %loop
+
+loop:
+ %i = phi i32 [ %i.next, %loop ], [ 0, %loop.preheader ]
+ %within.bounds = icmp ult i32 %i, %length
+ call void (i1, ...) @llvm.experimental.guard(i1 %within.bounds, i32 9) [ "deopt"() ]
+
+ %i.next = add nuw i32 %i, 2
+ %continue = icmp ne i32 %i.next, 400
+ br i1 %continue, label %loop, label %exit
+
+exit:
+ ret i32 0
+}
+
+; NE Latch - but end > start so wraps around and not equivelent to a ult
+define i32 @neg_ne_latch_swapped_order(i32* %array, i32 %length) {
+; CHECK-LABEL: @neg_ne_latch_swapped_order(
+; CHECK-NEXT: loop.preheader:
+; CHECK-NEXT: br label [[LOOP:%.*]]
+; CHECK: loop:
+; CHECK-NEXT: [[I:%.*]] = phi i32 [ [[I_NEXT:%.*]], [[LOOP]] ], [ 400, [[LOOP_PREHEADER:%.*]] ]
+; CHECK-NEXT: [[WITHIN_BOUNDS:%.*]] = icmp ult i32 [[I]], [[LENGTH:%.*]]
+; CHECK-NEXT: call void (i1, ...) @llvm.experimental.guard(i1 [[WITHIN_BOUNDS]], i32 9) [ "deopt"() ]
+; CHECK-NEXT: [[I_NEXT]] = add i32 [[I]], 1
+; CHECK-NEXT: [[CONTINUE:%.*]] = icmp ne i32 [[I_NEXT]], 0
+; CHECK-NEXT: br i1 [[CONTINUE]], label [[LOOP]], label [[EXIT:%.*]]
+; CHECK: exit:
+; CHECK-NEXT: ret i32 0
+;
+loop.preheader:
+ br label %loop
+
+loop:
+ %i = phi i32 [ %i.next, %loop ], [ 400, %loop.preheader ]
+ %within.bounds = icmp ult i32 %i, %length
+ call void (i1, ...) @llvm.experimental.guard(i1 %within.bounds, i32 9) [ "deopt"() ]
+
+ %i.next = add i32 %i, 1
+ %continue = icmp ne i32 %i.next, 0
+ br i1 %continue, label %loop, label %exit
+
+exit:
+ ret i32 0
+}
+
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