[llvm] c7d8581 - [IndVars] Add tests showing missed simplifications.

Florian Hahn via llvm-commits llvm-commits at lists.llvm.org
Mon Jun 16 08:31:46 PDT 2025


Author: Florian Hahn
Date: 2025-06-16T16:31:21+01:00
New Revision: c7d85813fda88329979ae6c091d59a60833a9765

URL: https://github.com/llvm/llvm-project/commit/c7d85813fda88329979ae6c091d59a60833a9765
DIFF: https://github.com/llvm/llvm-project/commit/c7d85813fda88329979ae6c091d59a60833a9765.diff

LOG: [IndVars] Add tests showing missed simplifications.

Added: 
    llvm/test/Transforms/IndVarSimplify/simplify-icmp-operands-order.ll

Modified: 
    

Removed: 
    


################################################################################
diff  --git a/llvm/test/Transforms/IndVarSimplify/simplify-icmp-operands-order.ll b/llvm/test/Transforms/IndVarSimplify/simplify-icmp-operands-order.ll
new file mode 100644
index 0000000000000..b0dbbd5eaedf4
--- /dev/null
+++ b/llvm/test/Transforms/IndVarSimplify/simplify-icmp-operands-order.ll
@@ -0,0 +1,193 @@
+; NOTE: Assertions have been autogenerated by utils/update_test_checks.py UTC_ARGS: --version 5
+; RUN: opt -p indvars -S %s | FileCheck %s
+
+target datalayout = "e-m:o-p270:32:32-p271:32:32-p272:64:64-i64:64-i128:128-n32:64-S128-Fn32"
+
+declare void @use(ptr)
+declare void @use.i64(i64)
+
+define i64 @test_simplifycompare_rhs_constant(i64 %num_bytes, ptr %src) {
+; CHECK-LABEL: define i64 @test_simplifycompare_rhs_constant(
+; CHECK-SAME: i64 [[NUM_BYTES:%.*]], ptr [[SRC:%.*]]) {
+; CHECK-NEXT:  [[ENTRY:.*]]:
+; CHECK-NEXT:    [[CMP_NOT_I:%.*]] = icmp ne i64 [[NUM_BYTES]], 0
+; CHECK-NEXT:    [[COND_I:%.*]] = zext i1 [[CMP_NOT_I]] to i64
+; CHECK-NEXT:    br label %[[LOOP:.*]]
+; CHECK:       [[LOOP]]:
+; CHECK-NEXT:    [[IV:%.*]] = phi i64 [ 1, %[[ENTRY]] ], [ [[IV_NEXT:%.*]], %[[LOOP_LATCH:.*]] ]
+; CHECK-NEXT:    [[C_0:%.*]] = icmp ule i64 [[IV]], [[COND_I]]
+; CHECK-NEXT:    tail call void @llvm.assume(i1 [[C_0]])
+; CHECK-NEXT:    [[GEP_SRC:%.*]] = getelementptr i32, ptr [[SRC]], i64 [[IV]]
+; CHECK-NEXT:    [[L:%.*]] = load i32, ptr [[GEP_SRC]], align 4
+; CHECK-NEXT:    [[C_1:%.*]] = icmp eq i32 [[L]], 0
+; CHECK-NEXT:    br i1 [[C_1]], label %[[THEN:.*]], label %[[LOOP_LATCH]]
+; CHECK:       [[THEN]]:
+; CHECK-NEXT:    call void @use(ptr [[SRC]])
+; CHECK-NEXT:    br label %[[LOOP_LATCH]]
+; CHECK:       [[LOOP_LATCH]]:
+; CHECK-NEXT:    [[IV_NEXT]] = add nuw nsw i64 [[IV]], 1
+; CHECK-NEXT:    br label %[[LOOP]]
+;
+entry:
+  %cmp.not.i = icmp ne i64 %num_bytes, 0
+  %cond.i = zext i1 %cmp.not.i to i64
+  br label %loop
+
+loop:
+  %iv = phi i64 [ 1, %entry ], [ %iv.next, %loop.latch ]
+  %c.0 = icmp ule i64 %iv, %cond.i
+  tail call void @llvm.assume(i1 %c.0)
+  %gep.src = getelementptr i32, ptr %src, i64 %iv
+  %l = load i32, ptr %gep.src, align 4
+  %c.1 = icmp eq i32 %l, 0
+  br i1 %c.1, label %then, label %loop.latch
+
+then:
+  call void @use(ptr %src)
+  br label %loop.latch
+
+loop.latch:
+  %iv.next = add i64 %iv, 1
+  br label %loop
+}
+
+define void @test_simplifycompare_rhs_not_constant1() {
+; CHECK-LABEL: define void @test_simplifycompare_rhs_not_constant1() {
+; CHECK-NEXT:  [[ENTRY:.*]]:
+; CHECK-NEXT:    [[P:%.*]] = alloca i64, align 8
+; CHECK-NEXT:    br label %[[LOOP:.*]]
+; CHECK:       [[LOOP]]:
+; CHECK-NEXT:    [[PTR_IV:%.*]] = phi ptr [ [[P]], %[[ENTRY]] ], [ [[PTR_IV_NEXT:%.*]], %[[LOOP]] ]
+; CHECK-NEXT:    [[PTR_IV_NEXT]] = getelementptr i8, ptr [[PTR_IV]], i64 -8
+; CHECK-NEXT:    call void @use(ptr [[PTR_IV]])
+; CHECK-NEXT:    [[EC:%.*]] = icmp ult ptr [[PTR_IV_NEXT]], [[P]]
+; CHECK-NEXT:    br i1 [[EC]], label %[[EXIT:.*]], label %[[LOOP]]
+; CHECK:       [[EXIT]]:
+; CHECK-NEXT:    ret void
+;
+entry:
+  %p = alloca i64, align 8
+  br label %loop
+
+loop:
+  %ptr.iv = phi ptr [ %p, %entry ], [ %ptr.iv.next, %loop ]
+  %ptr.iv.next = getelementptr i8, ptr %ptr.iv, i64 -8
+  call void @use(ptr %ptr.iv)
+  %ec = icmp ult ptr %ptr.iv.next, %p
+  br i1 %ec, label %exit, label %loop
+
+exit:
+  ret void
+}
+
+define void @test_simplifycompare_rhs_not_constant2(i32 %x) {
+; CHECK-LABEL: define void @test_simplifycompare_rhs_not_constant2(
+; CHECK-SAME: i32 [[X:%.*]]) {
+; CHECK-NEXT:  [[ENTRY:.*]]:
+; CHECK-NEXT:    br label %[[OUTER_HEADER:.*]]
+; CHECK:       [[OUTER_HEADER_LOOPEXIT:.*]]:
+; CHECK-NEXT:    [[INDVARS_IV_NEXT:%.*]] = add nuw i64 [[INDVARS_IV:%.*]], 2
+; CHECK-NEXT:    br label %[[OUTER_HEADER]]
+; CHECK:       [[OUTER_HEADER]]:
+; CHECK-NEXT:    [[INDVARS_IV]] = phi i64 [ [[INDVARS_IV_NEXT]], %[[OUTER_HEADER_LOOPEXIT]] ], [ 0, %[[ENTRY]] ]
+; CHECK-NEXT:    [[IV_1:%.*]] = phi i32 [ 0, %[[ENTRY]] ], [ [[IV_1_NEXT:%.*]], %[[OUTER_HEADER_LOOPEXIT]] ]
+; CHECK-NEXT:    [[C_1:%.*]] = icmp sgt i32 [[X]], 0
+; CHECK-NEXT:    br i1 [[C_1]], label %[[EXIT_LOOP_PREHEADER:.*]], label %[[OUTER_LATCH_PREHEADER:.*]]
+; CHECK:       [[EXIT_LOOP_PREHEADER]]:
+; CHECK-NEXT:    [[INDVARS_IV_LCSSA:%.*]] = phi i64 [ [[INDVARS_IV]], %[[OUTER_HEADER]] ]
+; CHECK-NEXT:    br label %[[EXIT_LOOP:.*]]
+; CHECK:       [[OUTER_LATCH_PREHEADER]]:
+; CHECK-NEXT:    [[IV_1_NEXT]] = add nuw nsw i32 [[IV_1]], 2
+; CHECK-NEXT:    br label %[[OUTER_LATCH:.*]]
+; CHECK:       [[OUTER_LATCH]]:
+; CHECK-NEXT:    [[P:%.*]] = phi i32 [ 0, %[[OUTER_LATCH_PREHEADER]] ], [ [[X]], %[[OUTER_LATCH]] ]
+; CHECK-NEXT:    [[C_2:%.*]] = icmp ult i32 [[P]], [[IV_1_NEXT]]
+; CHECK-NEXT:    br i1 [[C_2]], label %[[OUTER_LATCH]], label %[[OUTER_HEADER_LOOPEXIT]]
+; CHECK:       [[EXIT_LOOP]]:
+; CHECK-NEXT:    [[INDVARS_IV1:%.*]] = phi i64 [ [[INDVARS_IV_LCSSA]], %[[EXIT_LOOP_PREHEADER]] ], [ [[INDVARS_IV_NEXT2:%.*]], %[[EXIT_LOOP]] ]
+; CHECK-NEXT:    call void @use.i64(i64 [[INDVARS_IV1]])
+; CHECK-NEXT:    [[INDVARS_IV_NEXT2]] = add nuw nsw i64 [[INDVARS_IV1]], 1
+; CHECK-NEXT:    br label %[[EXIT_LOOP]]
+;
+entry:
+  br label %outer.header
+
+outer.header:
+  %iv.1 = phi i32 [ 0, %entry ], [ %iv.1.next, %outer.latch ]
+  %c.1 = icmp sgt i32 %x, 0
+  br i1 %c.1, label %exit.loop, label %outer.latch.preheader
+
+outer.latch.preheader:
+  %iv.1.next = add nsw i32 %iv.1, 2
+  br label %outer.latch
+
+outer.latch:
+  %p = phi i32 [ 0, %outer.latch.preheader ], [ %x, %outer.latch ]
+  %c.2 = icmp ult i32 %p, %iv.1.next
+  br i1 %c.2, label %outer.latch, label %outer.header
+
+exit.loop:
+  %iv.2 = phi i32 [ %iv.1, %outer.header ], [ %iv.2.next, %exit.loop ]
+  %iv.2.ext = zext i32 %iv.2 to i64
+  call void @use.i64(i64 %iv.2.ext)
+  %iv.2.next = add nsw i32 %iv.2, 1
+  br label %exit.loop
+}
+
+define void @test_simplifycompare_rhs_addrec(i32 %x) {
+; CHECK-LABEL: define void @test_simplifycompare_rhs_addrec(
+; CHECK-SAME: i32 [[X:%.*]]) {
+; CHECK-NEXT:  [[ENTRY:.*]]:
+; CHECK-NEXT:    br label %[[OUTER_HEADER:.*]]
+; CHECK:       [[OUTER_HEADER_LOOPEXIT:.*]]:
+; CHECK-NEXT:    [[INDVARS_IV_NEXT:%.*]] = add nuw nsw i64 [[INDVARS_IV:%.*]], 2
+; CHECK-NEXT:    br label %[[OUTER_HEADER]]
+; CHECK:       [[OUTER_HEADER]]:
+; CHECK-NEXT:    [[INDVARS_IV]] = phi i64 [ [[INDVARS_IV_NEXT]], %[[OUTER_HEADER_LOOPEXIT]] ], [ 0, %[[ENTRY]] ]
+; CHECK-NEXT:    [[IV_1:%.*]] = phi i32 [ 2, %[[ENTRY]] ], [ [[IV_1_NEXT:%.*]], %[[OUTER_HEADER_LOOPEXIT]] ]
+; CHECK-NEXT:    [[C_1:%.*]] = icmp sgt i32 [[X]], 0
+; CHECK-NEXT:    br i1 [[C_1]], label %[[OUTER_EXIT:.*]], label %[[OUTER_LATCH_PREHEADER:.*]]
+; CHECK:       [[OUTER_LATCH_PREHEADER]]:
+; CHECK-NEXT:    [[IV_1_NEXT]] = add nuw nsw i32 [[IV_1]], 2
+; CHECK-NEXT:    br label %[[OUTER_LATCH:.*]]
+; CHECK:       [[OUTER_LATCH]]:
+; CHECK-NEXT:    [[P:%.*]] = phi i32 [ [[X]], %[[OUTER_LATCH]] ], [ 0, %[[OUTER_LATCH_PREHEADER]] ]
+; CHECK-NEXT:    [[C_2:%.*]] = icmp ult i32 [[P]], [[IV_1_NEXT]]
+; CHECK-NEXT:    br i1 [[C_2]], label %[[OUTER_LATCH]], label %[[OUTER_HEADER_LOOPEXIT]]
+; CHECK:       [[OUTER_EXIT]]:
+; CHECK-NEXT:    [[INDVARS_IV_LCSSA:%.*]] = phi i64 [ [[INDVARS_IV]], %[[OUTER_HEADER]] ]
+; CHECK-NEXT:    br label %[[EXIT_LOOP:.*]]
+; CHECK:       [[EXIT_LOOP]]:
+; CHECK-NEXT:    [[INDVARS_IV1:%.*]] = phi i64 [ [[INDVARS_IV_NEXT2:%.*]], %[[EXIT_LOOP]] ], [ [[INDVARS_IV_LCSSA]], %[[OUTER_EXIT]] ]
+; CHECK-NEXT:    call void @use.i64(i64 [[INDVARS_IV1]])
+; CHECK-NEXT:    [[INDVARS_IV_NEXT2]] = add nuw nsw i64 [[INDVARS_IV1]], 1
+; CHECK-NEXT:    br label %[[EXIT_LOOP]]
+;
+entry:
+  br label %outer.header
+
+outer.header:
+  %iv.1 = phi i32 [ 2, %entry ], [ %iv.1.next, %outer.latch ]
+  %c.1 = icmp sgt i32 %x, 0
+  br i1 %c.1, label %outer.exit, label %outer.latch.preheader
+
+outer.latch.preheader:
+  %iv.1.next = add nuw nsw i32 %iv.1, 2
+  br label %outer.latch
+
+outer.latch:
+  %p = phi i32 [ %x, %outer.latch ], [ 0, %outer.latch.preheader ]
+  %c.2 = icmp ult i32 %p, %iv.1.next
+  br i1 %c.2, label %outer.latch, label %outer.header
+
+outer.exit:
+  %sub = add nsw i32 %iv.1, -2
+  br label %exit.loop
+
+exit.loop:
+  %iv.2 = phi i32 [ %sub, %outer.exit ], [ %iv.2.next, %exit.loop ]
+  %iv.2.ext = sext i32 %iv.2 to i64
+  call void @use.i64(i64 %iv.2.ext)
+  %iv.2.next = add nsw i32 %iv.2, 1
+  br label %exit.loop
+}


        


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