[llvm] 8e4ae60 - [Tests] Add tests for non-speculatable ephemeral values

[Nikita Popov via llvm-commits]

Author: Nikita Popov
Date: 2021-10-20T23:33:36+02:00
New Revision: 8e4ae603d6ec7658df86302d122fb24968524164

URL: https://github.com/llvm/llvm-project/commit/8e4ae603d6ec7658df86302d122fb24968524164
DIFF: https://github.com/llvm/llvm-project/commit/8e4ae603d6ec7658df86302d122fb24968524164.diff

LOG: [Tests] Add tests for non-speculatable ephemeral values

The loads in these examples are currently not considered ephemeral
because they are not speculatable.

Added: 
    

Modified: 
    llvm/test/Transforms/Inline/ephemeral.ll
    llvm/test/Transforms/SimplifyCFG/unprofitable-pr.ll

Removed: 
    


################################################################################
diff  --git a/llvm/test/Transforms/Inline/ephemeral.ll b/llvm/test/Transforms/Inline/ephemeral.ll
index 7d9bd7130fa3a..f47c349cb517b 100644
--- a/llvm/test/Transforms/Inline/ephemeral.ll
+++ b/llvm/test/Transforms/Inline/ephemeral.ll
@@ -1,11 +1,12 @@
 ; RUN: opt -S -inline %s -debug-only=inline-cost 2>&1 | FileCheck %s
 ; REQUIRES: asserts
-; Only the load and ret should be included in the instruction count, not
-; the instructions feeding the assume.
-; CHECK: NumInstructions: 2
 
 @a = global i32 4
 
+; Only the load and ret should be included in the instruction count, not
+; the instructions feeding the assume.
+; CHECK: Analyzing call of inner...
+; CHECK: NumInstructions: 2
 define i32 @inner(i8* %y) {
   %a1 = load volatile i32, i32* @a
 
@@ -25,8 +26,20 @@ define i32 @inner(i8* %y) {
   ret i32 %a1
 }
 
+; TODO: The load should be considered ephemeral here, even though it is not
+; speculatable.
+; CHECK: Analyzing call of inner2...
+; CHECK: NumInstructions: 2
+define void @inner2(i8* %y) {
+  %v = load i8, i8* %y
+  %c = icmp eq i8 %v, 42
+  call void @llvm.assume(i1 %c)
+  ret void
+}
+
 define i32 @outer(i8* %y) optsize {
    %r = call i32 @inner(i8* %y)
+   call void @inner2(i8* %y)
    ret i32 %r
 }
 

diff  --git a/llvm/test/Transforms/SimplifyCFG/unprofitable-pr.ll b/llvm/test/Transforms/SimplifyCFG/unprofitable-pr.ll
index 8d227cf989741..af918657b5701 100644
--- a/llvm/test/Transforms/SimplifyCFG/unprofitable-pr.ll
+++ b/llvm/test/Transforms/SimplifyCFG/unprofitable-pr.ll
@@ -232,3 +232,58 @@ false2:                                           ; preds = %true1
   store volatile i64 3, i64* %ptr, align 8
   ret void
 }
+
+; TODO: The load should be considered ephemeral here, even though it is not
+; speculatable.
+define void @test_non_speculatable(i1 %c, i64* align 1 %ptr, i8* %ptr2) local_unnamed_addr #0 {
+; CHECK-LABEL: @test_non_speculatable(
+; CHECK-NEXT:    br i1 [[C:%.*]], label [[TRUE1:%.*]], label [[FALSE1:%.*]]
+; CHECK:       true1:
+; CHECK-NEXT:    [[V:%.*]] = load i8, i8* [[PTR2:%.*]], align 1
+; CHECK-NEXT:    [[C2:%.*]] = icmp eq i8 [[V]], 42
+; CHECK-NEXT:    call void @llvm.assume(i1 [[C2]])
+; CHECK-NEXT:    store volatile i64 0, i64* [[PTR:%.*]], align 8
+; CHECK-NEXT:    store volatile i64 -1, i64* [[PTR]], align 8
+; CHECK-NEXT:    store volatile i64 -1, i64* [[PTR]], align 8
+; CHECK-NEXT:    store volatile i64 -1, i64* [[PTR]], align 8
+; CHECK-NEXT:    store volatile i64 -1, i64* [[PTR]], align 8
+; CHECK-NEXT:    store volatile i64 -1, i64* [[PTR]], align 8
+; CHECK-NEXT:    br i1 [[C]], label [[TRUE2:%.*]], label [[FALSE2:%.*]]
+; CHECK:       false1:
+; CHECK-NEXT:    store volatile i64 1, i64* [[PTR]], align 4
+; CHECK-NEXT:    br label [[TRUE1]]
+; CHECK:       common.ret:
+; CHECK-NEXT:    ret void
+; CHECK:       true2:
+; CHECK-NEXT:    store volatile i64 2, i64* [[PTR]], align 8
+; CHECK-NEXT:    br label [[COMMON_RET:%.*]]
+; CHECK:       false2:
+; CHECK-NEXT:    store volatile i64 3, i64* [[PTR]], align 8
+; CHECK-NEXT:    br label [[COMMON_RET]]
+;
+  br i1 %c, label %true1, label %false1
+
+true1:                                            ; preds = %false1, %0
+  %v = load i8, i8* %ptr2
+  %c2 = icmp eq i8 %v, 42
+  call void @llvm.assume(i1 %c2)
+  store volatile i64 0, i64* %ptr, align 8
+  store volatile i64 -1, i64* %ptr, align 8
+  store volatile i64 -1, i64* %ptr, align 8
+  store volatile i64 -1, i64* %ptr, align 8
+  store volatile i64 -1, i64* %ptr, align 8
+  store volatile i64 -1, i64* %ptr, align 8
+  br i1 %c, label %true2, label %false2
+
+false1:                                           ; preds = %0
+  store volatile i64 1, i64* %ptr, align 4
+  br label %true1
+
+true2:                                            ; preds = %true1
+  store volatile i64 2, i64* %ptr, align 8
+  ret void
+
+false2:                                           ; preds = %true1
+  store volatile i64 3, i64* %ptr, align 8
+  ret void
+}