[llvm] 45ddb24 - [NFC][LoopIdiom] Add basic test coverage for 'left-shift until bittest` idiom
Roman Lebedev via llvm-commits
llvm-commits at lists.llvm.org
Sun Nov 8 11:36:22 PST 2020
Author: Roman Lebedev
Date: 2020-11-08T22:35:41+03:00
New Revision: 45ddb245c50c2f3a109ad22174e9b52ad6de0ac7
URL: https://github.com/llvm/llvm-project/commit/45ddb245c50c2f3a109ad22174e9b52ad6de0ac7
DIFF: https://github.com/llvm/llvm-project/commit/45ddb245c50c2f3a109ad22174e9b52ad6de0ac7.diff
LOG: [NFC][LoopIdiom] Add basic test coverage for 'left-shift until bittest` idiom
Added:
llvm/test/Transforms/LoopIdiom/X86/left-shift-until-bittest.ll
Modified:
Removed:
################################################################################
diff --git a/llvm/test/Transforms/LoopIdiom/X86/left-shift-until-bittest.ll b/llvm/test/Transforms/LoopIdiom/X86/left-shift-until-bittest.ll
new file mode 100644
index 000000000000..6e3e5f7a273a
--- /dev/null
+++ b/llvm/test/Transforms/LoopIdiom/X86/left-shift-until-bittest.ll
@@ -0,0 +1,764 @@
+; NOTE: Assertions have been autogenerated by utils/update_test_checks.py
+; RUN: opt -debugify -loop-idiom -mtriple=x86_64 -mcpu=core-avx2 < %s -S | FileCheck -check-prefixes=ALL,LZCNT %s
+; RUN: opt -debugify -loop-idiom -mtriple=x86_64 -mcpu=corei7 < %s -S | FileCheck -check-prefixes=ALL,NOLZCNT %s
+
+declare i32 @gen32()
+declare void @use32(i32)
+declare void @use1(i1)
+declare void @external_side_effect()
+
+; The patterns here are all have the same base form:
+; while (!(x & (1U << bit)))
+; x <<= 1;
+; .. which is an uncountable loop.
+; We should transform it into it's countable form.
+
+; Most basic example.
+define i32 @p0_32(i32 %x, i32 %bit) {
+; ALL-LABEL: @p0_32(
+; ALL-NEXT: entry:
+; ALL-NEXT: [[BITMASK:%.*]] = shl i32 1, [[BIT:%.*]], [[DBG16:!dbg !.*]]
+; ALL-NEXT: call void @llvm.dbg.value(metadata i32 [[BITMASK]], [[META9:metadata !.*]], metadata !DIExpression()), [[DBG16]]
+; ALL-NEXT: br label [[LOOP:%.*]], [[DBG17:!dbg !.*]]
+; ALL: loop:
+; ALL-NEXT: [[X_CURR:%.*]] = phi i32 [ [[X:%.*]], [[ENTRY:%.*]] ], [ [[X_NEXT:%.*]], [[LOOP]] ], [[DBG18:!dbg !.*]]
+; ALL-NEXT: call void @llvm.dbg.value(metadata i32 [[X_CURR]], [[META11:metadata !.*]], metadata !DIExpression()), [[DBG18]]
+; ALL-NEXT: [[X_CURR_BITMASKED:%.*]] = and i32 [[X_CURR]], [[BITMASK]], [[DBG19:!dbg !.*]]
+; ALL-NEXT: call void @llvm.dbg.value(metadata i32 [[X_CURR_BITMASKED]], [[META12:metadata !.*]], metadata !DIExpression()), [[DBG19]]
+; ALL-NEXT: [[X_CURR_ISBITUNSET:%.*]] = icmp eq i32 [[X_CURR_BITMASKED]], 0, [[DBG20:!dbg !.*]]
+; ALL-NEXT: call void @llvm.dbg.value(metadata i1 [[X_CURR_ISBITUNSET]], [[META13:metadata !.*]], metadata !DIExpression()), [[DBG20]]
+; ALL-NEXT: [[X_NEXT]] = shl i32 [[X_CURR]], 1, [[DBG21:!dbg !.*]]
+; ALL-NEXT: call void @llvm.dbg.value(metadata i32 [[X_NEXT]], [[META15:metadata !.*]], metadata !DIExpression()), [[DBG21]]
+; ALL-NEXT: br i1 [[X_CURR_ISBITUNSET]], label [[LOOP]], label [[END:%.*]], [[DBG22:!dbg !.*]]
+; ALL: end:
+; ALL-NEXT: [[X_CURR_LCSSA:%.*]] = phi i32 [ [[X_CURR]], [[LOOP]] ], [[DBG18]]
+; ALL-NEXT: call void @llvm.dbg.value(metadata i32 [[X_CURR_LCSSA]], [[META11]], metadata !DIExpression()), [[DBG18]]
+; ALL-NEXT: ret i32 [[X_CURR_LCSSA]], [[DBG23:!dbg !.*]]
+;
+entry:
+ %bitmask = shl i32 1, %bit
+ br label %loop
+
+loop:
+ %x.curr = phi i32 [ %x, %entry ], [ %x.next, %loop ]
+ %x.curr.bitmasked = and i32 %x.curr, %bitmask
+ %x.curr.isbitunset = icmp eq i32 %x.curr.bitmasked, 0
+ %x.next = shl i32 %x.curr, 1
+ br i1 %x.curr.isbitunset, label %loop, label %end
+
+end:
+ ret i32 %x.curr
+}
+
+; Same, but in some other bit width.
+define i16 @p0_16(i16 %x, i16 %bit) {
+; ALL-LABEL: @p0_16(
+; ALL-NEXT: entry:
+; ALL-NEXT: [[BITMASK:%.*]] = shl i16 1, [[BIT:%.*]], [[DBG32:!dbg !.*]]
+; ALL-NEXT: call void @llvm.dbg.value(metadata i16 [[BITMASK]], [[META26:metadata !.*]], metadata !DIExpression()), [[DBG32]]
+; ALL-NEXT: br label [[LOOP:%.*]], [[DBG33:!dbg !.*]]
+; ALL: loop:
+; ALL-NEXT: [[X_CURR:%.*]] = phi i16 [ [[X:%.*]], [[ENTRY:%.*]] ], [ [[X_NEXT:%.*]], [[LOOP]] ], [[DBG34:!dbg !.*]]
+; ALL-NEXT: call void @llvm.dbg.value(metadata i16 [[X_CURR]], [[META28:metadata !.*]], metadata !DIExpression()), [[DBG34]]
+; ALL-NEXT: [[X_CURR_BITMASKED:%.*]] = and i16 [[X_CURR]], [[BITMASK]], [[DBG35:!dbg !.*]]
+; ALL-NEXT: call void @llvm.dbg.value(metadata i16 [[X_CURR_BITMASKED]], [[META29:metadata !.*]], metadata !DIExpression()), [[DBG35]]
+; ALL-NEXT: [[X_CURR_ISBITUNSET:%.*]] = icmp eq i16 [[X_CURR_BITMASKED]], 0, [[DBG36:!dbg !.*]]
+; ALL-NEXT: call void @llvm.dbg.value(metadata i1 [[X_CURR_ISBITUNSET]], [[META30:metadata !.*]], metadata !DIExpression()), [[DBG36]]
+; ALL-NEXT: [[X_NEXT]] = shl i16 [[X_CURR]], 1, [[DBG37:!dbg !.*]]
+; ALL-NEXT: call void @llvm.dbg.value(metadata i16 [[X_NEXT]], [[META31:metadata !.*]], metadata !DIExpression()), [[DBG37]]
+; ALL-NEXT: br i1 [[X_CURR_ISBITUNSET]], label [[LOOP]], label [[END:%.*]], [[DBG38:!dbg !.*]]
+; ALL: end:
+; ALL-NEXT: [[X_CURR_LCSSA:%.*]] = phi i16 [ [[X_CURR]], [[LOOP]] ], [[DBG34]]
+; ALL-NEXT: call void @llvm.dbg.value(metadata i16 [[X_CURR_LCSSA]], [[META28]], metadata !DIExpression()), [[DBG34]]
+; ALL-NEXT: ret i16 [[X_CURR_LCSSA]], [[DBG39:!dbg !.*]]
+;
+entry:
+ %bitmask = shl i16 1, %bit
+ br label %loop
+
+loop:
+ %x.curr = phi i16 [ %x, %entry ], [ %x.next, %loop ]
+ %x.curr.bitmasked = and i16 %x.curr, %bitmask
+ %x.curr.isbitunset = icmp eq i16 %x.curr.bitmasked, 0
+ %x.next = shl i16 %x.curr, 1
+ br i1 %x.curr.isbitunset, label %loop, label %end
+
+end:
+ ret i16 %x.curr
+}
+
+; Check that loop backedge's cmp-br order is correctly handled
+define i32 @p1(i32 %x, i32 %bit) {
+; ALL-LABEL: @p1(
+; ALL-NEXT: entry:
+; ALL-NEXT: [[BITMASK:%.*]] = shl i32 1, [[BIT:%.*]], [[DBG47:!dbg !.*]]
+; ALL-NEXT: call void @llvm.dbg.value(metadata i32 [[BITMASK]], [[META42:metadata !.*]], metadata !DIExpression()), [[DBG47]]
+; ALL-NEXT: br label [[LOOP:%.*]], [[DBG48:!dbg !.*]]
+; ALL: loop:
+; ALL-NEXT: [[X_CURR:%.*]] = phi i32 [ [[X:%.*]], [[ENTRY:%.*]] ], [ [[X_NEXT:%.*]], [[LOOP]] ], [[DBG49:!dbg !.*]]
+; ALL-NEXT: call void @llvm.dbg.value(metadata i32 [[X_CURR]], [[META43:metadata !.*]], metadata !DIExpression()), [[DBG49]]
+; ALL-NEXT: [[X_CURR_BITMASKED:%.*]] = and i32 [[X_CURR]], [[BITMASK]], [[DBG50:!dbg !.*]]
+; ALL-NEXT: call void @llvm.dbg.value(metadata i32 [[X_CURR_BITMASKED]], [[META44:metadata !.*]], metadata !DIExpression()), [[DBG50]]
+; ALL-NEXT: [[X_CURR_ISBITUNSET:%.*]] = icmp ne i32 [[X_CURR_BITMASKED]], 0, [[DBG51:!dbg !.*]]
+; ALL-NEXT: call void @llvm.dbg.value(metadata i1 [[X_CURR_ISBITUNSET]], [[META45:metadata !.*]], metadata !DIExpression()), [[DBG51]]
+; ALL-NEXT: [[X_NEXT]] = shl i32 [[X_CURR]], 1, [[DBG52:!dbg !.*]]
+; ALL-NEXT: call void @llvm.dbg.value(metadata i32 [[X_NEXT]], [[META46:metadata !.*]], metadata !DIExpression()), [[DBG52]]
+; ALL-NEXT: br i1 [[X_CURR_ISBITUNSET]], label [[END:%.*]], label [[LOOP]], [[DBG53:!dbg !.*]]
+; ALL: end:
+; ALL-NEXT: [[X_CURR_LCSSA:%.*]] = phi i32 [ [[X_CURR]], [[LOOP]] ], [[DBG49]]
+; ALL-NEXT: call void @llvm.dbg.value(metadata i32 [[X_CURR_LCSSA]], [[META43]], metadata !DIExpression()), [[DBG49]]
+; ALL-NEXT: ret i32 [[X_CURR_LCSSA]], [[DBG54:!dbg !.*]]
+;
+entry:
+ %bitmask = shl i32 1, %bit
+ br label %loop
+
+loop:
+ %x.curr = phi i32 [ %x, %entry ], [ %x.next, %loop ]
+ %x.curr.bitmasked = and i32 %x.curr, %bitmask
+ %x.curr.isbitunset = icmp ne i32 %x.curr.bitmasked, 0 ; swapped predicate
+ %x.next = shl i32 %x.curr, 1
+ br i1 %x.curr.isbitunset, label %end, label %loop ; swapped dests
+
+end:
+ ret i32 %x.curr
+}
+
+; `and` is commutative, so ensure that order is irrelevant
+define i32 @p2(i32 %x, i32 %bit) {
+; ALL-LABEL: @p2(
+; ALL-NEXT: entry:
+; ALL-NEXT: [[BITMASK:%.*]] = shl i32 1, [[BIT:%.*]], [[DBG62:!dbg !.*]]
+; ALL-NEXT: call void @llvm.dbg.value(metadata i32 [[BITMASK]], [[META57:metadata !.*]], metadata !DIExpression()), [[DBG62]]
+; ALL-NEXT: br label [[LOOP:%.*]], [[DBG63:!dbg !.*]]
+; ALL: loop:
+; ALL-NEXT: [[X_CURR:%.*]] = phi i32 [ [[X:%.*]], [[ENTRY:%.*]] ], [ [[X_NEXT:%.*]], [[LOOP]] ], [[DBG64:!dbg !.*]]
+; ALL-NEXT: call void @llvm.dbg.value(metadata i32 [[X_CURR]], [[META58:metadata !.*]], metadata !DIExpression()), [[DBG64]]
+; ALL-NEXT: [[X_CURR_BITMASKED:%.*]] = and i32 [[BITMASK]], [[X_CURR]], [[DBG65:!dbg !.*]]
+; ALL-NEXT: call void @llvm.dbg.value(metadata i32 [[X_CURR_BITMASKED]], [[META59:metadata !.*]], metadata !DIExpression()), [[DBG65]]
+; ALL-NEXT: [[X_CURR_ISBITUNSET:%.*]] = icmp eq i32 [[X_CURR_BITMASKED]], 0, [[DBG66:!dbg !.*]]
+; ALL-NEXT: call void @llvm.dbg.value(metadata i1 [[X_CURR_ISBITUNSET]], [[META60:metadata !.*]], metadata !DIExpression()), [[DBG66]]
+; ALL-NEXT: [[X_NEXT]] = shl i32 [[X_CURR]], 1, [[DBG67:!dbg !.*]]
+; ALL-NEXT: call void @llvm.dbg.value(metadata i32 [[X_NEXT]], [[META61:metadata !.*]], metadata !DIExpression()), [[DBG67]]
+; ALL-NEXT: br i1 [[X_CURR_ISBITUNSET]], label [[LOOP]], label [[END:%.*]], [[DBG68:!dbg !.*]]
+; ALL: end:
+; ALL-NEXT: [[X_CURR_LCSSA:%.*]] = phi i32 [ [[X_CURR]], [[LOOP]] ], [[DBG64]]
+; ALL-NEXT: call void @llvm.dbg.value(metadata i32 [[X_CURR_LCSSA]], [[META58]], metadata !DIExpression()), [[DBG64]]
+; ALL-NEXT: ret i32 [[X_CURR_LCSSA]], [[DBG69:!dbg !.*]]
+;
+entry:
+ %bitmask = shl i32 1, %bit
+ br label %loop
+
+loop:
+ %x.curr = phi i32 [ %x, %entry ], [ %x.next, %loop ]
+ %x.curr.bitmasked = and i32 %bitmask, %x.curr ; swapped
+ %x.curr.isbitunset = icmp eq i32 %x.curr.bitmasked, 0
+ %x.next = shl i32 %x.curr, 1
+ br i1 %x.curr.isbitunset, label %loop, label %end
+
+end:
+ ret i32 %x.curr
+}
+
+; PHI node does not have any particular order for it's incomings,
+; but check that the other order still works.
+define i32 @p3(i32 %x, i32 %bit) {
+; ALL-LABEL: @p3(
+; ALL-NEXT: entry:
+; ALL-NEXT: [[BITMASK:%.*]] = shl i32 1, [[BIT:%.*]], [[DBG77:!dbg !.*]]
+; ALL-NEXT: call void @llvm.dbg.value(metadata i32 [[BITMASK]], [[META72:metadata !.*]], metadata !DIExpression()), [[DBG77]]
+; ALL-NEXT: br label [[LOOP:%.*]], [[DBG78:!dbg !.*]]
+; ALL: loop:
+; ALL-NEXT: [[X_CURR:%.*]] = phi i32 [ [[X_NEXT:%.*]], [[LOOP]] ], [ [[X:%.*]], [[ENTRY:%.*]] ], [[DBG79:!dbg !.*]]
+; ALL-NEXT: call void @llvm.dbg.value(metadata i32 [[X_CURR]], [[META73:metadata !.*]], metadata !DIExpression()), [[DBG79]]
+; ALL-NEXT: [[X_CURR_BITMASKED:%.*]] = and i32 [[X_CURR]], [[BITMASK]], [[DBG80:!dbg !.*]]
+; ALL-NEXT: call void @llvm.dbg.value(metadata i32 [[X_CURR_BITMASKED]], [[META74:metadata !.*]], metadata !DIExpression()), [[DBG80]]
+; ALL-NEXT: [[X_CURR_ISBITUNSET:%.*]] = icmp eq i32 [[X_CURR_BITMASKED]], 0, [[DBG81:!dbg !.*]]
+; ALL-NEXT: call void @llvm.dbg.value(metadata i1 [[X_CURR_ISBITUNSET]], [[META75:metadata !.*]], metadata !DIExpression()), [[DBG81]]
+; ALL-NEXT: [[X_NEXT]] = shl i32 [[X_CURR]], 1, [[DBG82:!dbg !.*]]
+; ALL-NEXT: call void @llvm.dbg.value(metadata i32 [[X_NEXT]], [[META76:metadata !.*]], metadata !DIExpression()), [[DBG82]]
+; ALL-NEXT: br i1 [[X_CURR_ISBITUNSET]], label [[LOOP]], label [[END:%.*]], [[DBG83:!dbg !.*]]
+; ALL: end:
+; ALL-NEXT: [[X_CURR_LCSSA:%.*]] = phi i32 [ [[X_CURR]], [[LOOP]] ], [[DBG79]]
+; ALL-NEXT: call void @llvm.dbg.value(metadata i32 [[X_CURR_LCSSA]], [[META73]], metadata !DIExpression()), [[DBG79]]
+; ALL-NEXT: ret i32 [[X_CURR_LCSSA]], [[DBG84:!dbg !.*]]
+;
+entry:
+ %bitmask = shl i32 1, %bit
+ br label %loop
+
+loop:
+ %x.curr = phi i32 [ %x.next, %loop ], [ %x, %entry ]
+ %x.curr.bitmasked = and i32 %x.curr, %bitmask
+ %x.curr.isbitunset = icmp eq i32 %x.curr.bitmasked, 0
+ %x.next = shl i32 %x.curr, 1
+ br i1 %x.curr.isbitunset, label %loop, label %end
+
+end:
+ ret i32 %x.curr
+}
+
+;-------------------------------------------------------------------------------
+; Negative tests
+
+; The %bitmask must be outside of the loop.
+define i32 @n4(i32 %x, i32 %bit) {
+; ALL-LABEL: @n4(
+; ALL-NEXT: entry:
+; ALL-NEXT: br label [[LOOP:%.*]], [[DBG92:!dbg !.*]]
+; ALL: loop:
+; ALL-NEXT: [[X_CURR:%.*]] = phi i32 [ [[X:%.*]], [[ENTRY:%.*]] ], [ [[X_NEXT:%.*]], [[LOOP]] ], [[DBG93:!dbg !.*]]
+; ALL-NEXT: call void @llvm.dbg.value(metadata i32 [[X_CURR]], [[META87:metadata !.*]], metadata !DIExpression()), [[DBG93]]
+; ALL-NEXT: [[BITMASK:%.*]] = shl i32 1, [[BIT:%.*]], [[DBG94:!dbg !.*]]
+; ALL-NEXT: call void @llvm.dbg.value(metadata i32 [[BITMASK]], [[META88:metadata !.*]], metadata !DIExpression()), [[DBG94]]
+; ALL-NEXT: [[X_CURR_BITMASKED:%.*]] = and i32 [[X_CURR]], [[BITMASK]], [[DBG95:!dbg !.*]]
+; ALL-NEXT: call void @llvm.dbg.value(metadata i32 [[X_CURR_BITMASKED]], [[META89:metadata !.*]], metadata !DIExpression()), [[DBG95]]
+; ALL-NEXT: [[X_CURR_ISBITUNSET:%.*]] = icmp eq i32 [[X_CURR_BITMASKED]], 0, [[DBG96:!dbg !.*]]
+; ALL-NEXT: call void @llvm.dbg.value(metadata i1 [[X_CURR_ISBITUNSET]], [[META90:metadata !.*]], metadata !DIExpression()), [[DBG96]]
+; ALL-NEXT: [[X_NEXT]] = shl i32 [[X_CURR]], 1, [[DBG97:!dbg !.*]]
+; ALL-NEXT: call void @llvm.dbg.value(metadata i32 [[X_NEXT]], [[META91:metadata !.*]], metadata !DIExpression()), [[DBG97]]
+; ALL-NEXT: br i1 [[X_CURR_ISBITUNSET]], label [[LOOP]], label [[END:%.*]], [[DBG98:!dbg !.*]]
+; ALL: end:
+; ALL-NEXT: [[X_CURR_LCSSA:%.*]] = phi i32 [ [[X_CURR]], [[LOOP]] ], [[DBG93]]
+; ALL-NEXT: call void @llvm.dbg.value(metadata i32 [[X_CURR_LCSSA]], [[META87]], metadata !DIExpression()), [[DBG93]]
+; ALL-NEXT: ret i32 [[X_CURR_LCSSA]], [[DBG99:!dbg !.*]]
+;
+entry:
+ br label %loop
+
+loop:
+ %x.curr = phi i32 [ %x, %entry ], [ %x.next, %loop ]
+ %bitmask = shl i32 1, %bit ; not loop-invariant
+ %x.curr.bitmasked = and i32 %x.curr, %bitmask
+ %x.curr.isbitunset = icmp eq i32 %x.curr.bitmasked, 0
+ %x.next = shl i32 %x.curr, 1
+ br i1 %x.curr.isbitunset, label %loop, label %end
+
+end:
+ ret i32 %x.curr
+}
+
+; The %bitmask must be loop-invariant
+define i32 @n5(i32 %x, i32 %bit) {
+; ALL-LABEL: @n5(
+; ALL-NEXT: entry:
+; ALL-NEXT: br label [[LOOP:%.*]], [[DBG107:!dbg !.*]]
+; ALL: loop:
+; ALL-NEXT: [[X_CURR:%.*]] = phi i32 [ [[X:%.*]], [[ENTRY:%.*]] ], [ [[X_NEXT:%.*]], [[LOOP]] ], [[DBG108:!dbg !.*]]
+; ALL-NEXT: call void @llvm.dbg.value(metadata i32 [[X_CURR]], [[META102:metadata !.*]], metadata !DIExpression()), [[DBG108]]
+; ALL-NEXT: [[BITMASK:%.*]] = call i32 @gen32(), [[DBG109:!dbg !.*]]
+; ALL-NEXT: call void @llvm.dbg.value(metadata i32 [[BITMASK]], [[META103:metadata !.*]], metadata !DIExpression()), [[DBG109]]
+; ALL-NEXT: [[X_CURR_BITMASKED:%.*]] = and i32 [[X_CURR]], [[BITMASK]], [[DBG110:!dbg !.*]]
+; ALL-NEXT: call void @llvm.dbg.value(metadata i32 [[X_CURR_BITMASKED]], [[META104:metadata !.*]], metadata !DIExpression()), [[DBG110]]
+; ALL-NEXT: [[X_CURR_ISBITUNSET:%.*]] = icmp eq i32 [[X_CURR_BITMASKED]], 0, [[DBG111:!dbg !.*]]
+; ALL-NEXT: call void @llvm.dbg.value(metadata i1 [[X_CURR_ISBITUNSET]], [[META105:metadata !.*]], metadata !DIExpression()), [[DBG111]]
+; ALL-NEXT: [[X_NEXT]] = shl i32 [[X_CURR]], 1, [[DBG112:!dbg !.*]]
+; ALL-NEXT: call void @llvm.dbg.value(metadata i32 [[X_NEXT]], [[META106:metadata !.*]], metadata !DIExpression()), [[DBG112]]
+; ALL-NEXT: br i1 [[X_CURR_ISBITUNSET]], label [[LOOP]], label [[END:%.*]], [[DBG113:!dbg !.*]]
+; ALL: end:
+; ALL-NEXT: [[X_CURR_LCSSA:%.*]] = phi i32 [ [[X_CURR]], [[LOOP]] ], [[DBG108]]
+; ALL-NEXT: call void @llvm.dbg.value(metadata i32 [[X_CURR_LCSSA]], [[META102]], metadata !DIExpression()), [[DBG108]]
+; ALL-NEXT: ret i32 [[X_CURR_LCSSA]], [[DBG114:!dbg !.*]]
+;
+entry:
+ br label %loop
+
+loop:
+ %x.curr = phi i32 [ %x, %entry ], [ %x.next, %loop ]
+ %bitmask = call i32 @gen32() ; really not loop-invariant
+ %x.curr.bitmasked = and i32 %x.curr, %bitmask
+ %x.curr.isbitunset = icmp eq i32 %x.curr.bitmasked, 0
+ %x.next = shl i32 %x.curr, 1
+ br i1 %x.curr.isbitunset, label %loop, label %end
+
+end:
+ ret i32 %x.curr
+}
+
+; The %bitmask must be a left-shift of a single bit.
+define i32 @n6(i32 %x, i32 %bit) {
+; ALL-LABEL: @n6(
+; ALL-NEXT: entry:
+; ALL-NEXT: [[BITMASK:%.*]] = shl i32 2, [[BIT:%.*]], [[DBG122:!dbg !.*]]
+; ALL-NEXT: call void @llvm.dbg.value(metadata i32 [[BITMASK]], [[META117:metadata !.*]], metadata !DIExpression()), [[DBG122]]
+; ALL-NEXT: br label [[LOOP:%.*]], [[DBG123:!dbg !.*]]
+; ALL: loop:
+; ALL-NEXT: [[X_CURR:%.*]] = phi i32 [ [[X:%.*]], [[ENTRY:%.*]] ], [ [[X_NEXT:%.*]], [[LOOP]] ], [[DBG124:!dbg !.*]]
+; ALL-NEXT: call void @llvm.dbg.value(metadata i32 [[X_CURR]], [[META118:metadata !.*]], metadata !DIExpression()), [[DBG124]]
+; ALL-NEXT: [[X_CURR_BITMASKED:%.*]] = and i32 [[X_CURR]], [[BITMASK]], [[DBG125:!dbg !.*]]
+; ALL-NEXT: call void @llvm.dbg.value(metadata i32 [[X_CURR_BITMASKED]], [[META119:metadata !.*]], metadata !DIExpression()), [[DBG125]]
+; ALL-NEXT: [[X_CURR_ISBITUNSET:%.*]] = icmp eq i32 [[X_CURR_BITMASKED]], 0, [[DBG126:!dbg !.*]]
+; ALL-NEXT: call void @llvm.dbg.value(metadata i1 [[X_CURR_ISBITUNSET]], [[META120:metadata !.*]], metadata !DIExpression()), [[DBG126]]
+; ALL-NEXT: [[X_NEXT]] = shl i32 [[X_CURR]], 1, [[DBG127:!dbg !.*]]
+; ALL-NEXT: call void @llvm.dbg.value(metadata i32 [[X_NEXT]], [[META121:metadata !.*]], metadata !DIExpression()), [[DBG127]]
+; ALL-NEXT: br i1 [[X_CURR_ISBITUNSET]], label [[LOOP]], label [[END:%.*]], [[DBG128:!dbg !.*]]
+; ALL: end:
+; ALL-NEXT: [[X_CURR_LCSSA:%.*]] = phi i32 [ [[X_CURR]], [[LOOP]] ], [[DBG124]]
+; ALL-NEXT: call void @llvm.dbg.value(metadata i32 [[X_CURR_LCSSA]], [[META118]], metadata !DIExpression()), [[DBG124]]
+; ALL-NEXT: ret i32 [[X_CURR_LCSSA]], [[DBG129:!dbg !.*]]
+;
+entry:
+ %bitmask = shl i32 2, %bit ; not what we are looking for.
+ br label %loop
+
+loop:
+ %x.curr = phi i32 [ %x, %entry ], [ %x.next, %loop ]
+ %x.curr.bitmasked = and i32 %x.curr, %bitmask
+ %x.curr.isbitunset = icmp eq i32 %x.curr.bitmasked, 0
+ %x.next = shl i32 %x.curr, 1
+ br i1 %x.curr.isbitunset, label %loop, label %end
+
+end:
+ ret i32 %x.curr
+}
+
+; Bad recurrence - should be a left-shift by 1.
+define i32 @n7(i32 %x, i32 %bit) {
+; ALL-LABEL: @n7(
+; ALL-NEXT: entry:
+; ALL-NEXT: [[BITMASK:%.*]] = shl i32 1, [[BIT:%.*]], [[DBG137:!dbg !.*]]
+; ALL-NEXT: call void @llvm.dbg.value(metadata i32 [[BITMASK]], [[META132:metadata !.*]], metadata !DIExpression()), [[DBG137]]
+; ALL-NEXT: br label [[LOOP:%.*]], [[DBG138:!dbg !.*]]
+; ALL: loop:
+; ALL-NEXT: [[X_CURR:%.*]] = phi i32 [ [[X:%.*]], [[ENTRY:%.*]] ], [ [[X_NEXT:%.*]], [[LOOP]] ], [[DBG139:!dbg !.*]]
+; ALL-NEXT: call void @llvm.dbg.value(metadata i32 [[X_CURR]], [[META133:metadata !.*]], metadata !DIExpression()), [[DBG139]]
+; ALL-NEXT: [[X_CURR_BITMASKED:%.*]] = and i32 [[X_CURR]], [[BITMASK]], [[DBG140:!dbg !.*]]
+; ALL-NEXT: call void @llvm.dbg.value(metadata i32 [[X_CURR_BITMASKED]], [[META134:metadata !.*]], metadata !DIExpression()), [[DBG140]]
+; ALL-NEXT: [[X_CURR_ISBITUNSET:%.*]] = icmp eq i32 [[X_CURR_BITMASKED]], 0, [[DBG141:!dbg !.*]]
+; ALL-NEXT: call void @llvm.dbg.value(metadata i1 [[X_CURR_ISBITUNSET]], [[META135:metadata !.*]], metadata !DIExpression()), [[DBG141]]
+; ALL-NEXT: [[X_NEXT]] = shl i32 [[X_CURR]], 2, [[DBG142:!dbg !.*]]
+; ALL-NEXT: call void @llvm.dbg.value(metadata i32 [[X_NEXT]], [[META136:metadata !.*]], metadata !DIExpression()), [[DBG142]]
+; ALL-NEXT: br i1 [[X_CURR_ISBITUNSET]], label [[LOOP]], label [[END:%.*]], [[DBG143:!dbg !.*]]
+; ALL: end:
+; ALL-NEXT: [[X_CURR_LCSSA:%.*]] = phi i32 [ [[X_CURR]], [[LOOP]] ], [[DBG139]]
+; ALL-NEXT: call void @llvm.dbg.value(metadata i32 [[X_CURR_LCSSA]], [[META133]], metadata !DIExpression()), [[DBG139]]
+; ALL-NEXT: ret i32 [[X_CURR_LCSSA]], [[DBG144:!dbg !.*]]
+;
+entry:
+ %bitmask = shl i32 1, %bit
+ br label %loop
+
+loop:
+ %x.curr = phi i32 [ %x, %entry ], [ %x.next, %loop ]
+ %x.curr.bitmasked = and i32 %x.curr, %bitmask
+ %x.curr.isbitunset = icmp eq i32 %x.curr.bitmasked, 0
+ %x.next = shl i32 %x.curr, 2 ; wrong shift amount.
+ br i1 %x.curr.isbitunset, label %loop, label %end
+
+end:
+ ret i32 %x.curr
+}
+
+; The comparison is not what we are looking for.
+define i32 @n8(i32 %x, i32 %bit) {
+; ALL-LABEL: @n8(
+; ALL-NEXT: entry:
+; ALL-NEXT: [[BITMASK:%.*]] = shl i32 1, [[BIT:%.*]], [[DBG152:!dbg !.*]]
+; ALL-NEXT: call void @llvm.dbg.value(metadata i32 [[BITMASK]], [[META147:metadata !.*]], metadata !DIExpression()), [[DBG152]]
+; ALL-NEXT: br label [[LOOP:%.*]], [[DBG153:!dbg !.*]]
+; ALL: loop:
+; ALL-NEXT: [[X_CURR:%.*]] = phi i32 [ [[X:%.*]], [[ENTRY:%.*]] ], [ [[X_NEXT:%.*]], [[LOOP]] ], [[DBG154:!dbg !.*]]
+; ALL-NEXT: call void @llvm.dbg.value(metadata i32 [[X_CURR]], [[META148:metadata !.*]], metadata !DIExpression()), [[DBG154]]
+; ALL-NEXT: [[X_CURR_BITMASKED:%.*]] = and i32 [[X_CURR]], [[BITMASK]], [[DBG155:!dbg !.*]]
+; ALL-NEXT: call void @llvm.dbg.value(metadata i32 [[X_CURR_BITMASKED]], [[META149:metadata !.*]], metadata !DIExpression()), [[DBG155]]
+; ALL-NEXT: [[X_CURR_ISBITUNSET:%.*]] = icmp ne i32 [[X_CURR_BITMASKED]], [[BITMASK]], [[DBG156:!dbg !.*]]
+; ALL-NEXT: call void @llvm.dbg.value(metadata i1 [[X_CURR_ISBITUNSET]], [[META150:metadata !.*]], metadata !DIExpression()), [[DBG156]]
+; ALL-NEXT: [[X_NEXT]] = shl i32 [[X_CURR]], 1, [[DBG157:!dbg !.*]]
+; ALL-NEXT: call void @llvm.dbg.value(metadata i32 [[X_NEXT]], [[META151:metadata !.*]], metadata !DIExpression()), [[DBG157]]
+; ALL-NEXT: br i1 [[X_CURR_ISBITUNSET]], label [[LOOP]], label [[END:%.*]], [[DBG158:!dbg !.*]]
+; ALL: end:
+; ALL-NEXT: [[X_CURR_LCSSA:%.*]] = phi i32 [ [[X_CURR]], [[LOOP]] ], [[DBG154]]
+; ALL-NEXT: call void @llvm.dbg.value(metadata i32 [[X_CURR_LCSSA]], [[META148]], metadata !DIExpression()), [[DBG154]]
+; ALL-NEXT: ret i32 [[X_CURR_LCSSA]], [[DBG159:!dbg !.*]]
+;
+entry:
+ %bitmask = shl i32 1, %bit
+ br label %loop
+
+loop:
+ %x.curr = phi i32 [ %x, %entry ], [ %x.next, %loop ]
+ %x.curr.bitmasked = and i32 %x.curr, %bitmask
+ %x.curr.isbitunset = icmp ne i32 %x.curr.bitmasked, %bitmask ; should be `==0`
+ %x.next = shl i32 %x.curr, 1
+ br i1 %x.curr.isbitunset, label %loop, label %end
+
+end:
+ ret i32 %x.curr
+}
+
+; We should loop while %x.curr.bitmasked is 0, not exit when it is 0.
+define i32 @n9(i32 %x, i32 %bit) {
+; ALL-LABEL: @n9(
+; ALL-NEXT: entry:
+; ALL-NEXT: [[BITMASK:%.*]] = shl i32 1, [[BIT:%.*]], [[DBG167:!dbg !.*]]
+; ALL-NEXT: call void @llvm.dbg.value(metadata i32 [[BITMASK]], [[META162:metadata !.*]], metadata !DIExpression()), [[DBG167]]
+; ALL-NEXT: br label [[LOOP:%.*]], [[DBG168:!dbg !.*]]
+; ALL: loop:
+; ALL-NEXT: [[X_CURR:%.*]] = phi i32 [ [[X:%.*]], [[ENTRY:%.*]] ], [ [[X_NEXT:%.*]], [[LOOP]] ], [[DBG169:!dbg !.*]]
+; ALL-NEXT: call void @llvm.dbg.value(metadata i32 [[X_CURR]], [[META163:metadata !.*]], metadata !DIExpression()), [[DBG169]]
+; ALL-NEXT: [[X_CURR_BITMASKED:%.*]] = and i32 [[X_CURR]], [[BITMASK]], [[DBG170:!dbg !.*]]
+; ALL-NEXT: call void @llvm.dbg.value(metadata i32 [[X_CURR_BITMASKED]], [[META164:metadata !.*]], metadata !DIExpression()), [[DBG170]]
+; ALL-NEXT: [[X_CURR_ISBITUNSET:%.*]] = icmp eq i32 [[X_CURR_BITMASKED]], 0, [[DBG171:!dbg !.*]]
+; ALL-NEXT: call void @llvm.dbg.value(metadata i1 [[X_CURR_ISBITUNSET]], [[META165:metadata !.*]], metadata !DIExpression()), [[DBG171]]
+; ALL-NEXT: [[X_NEXT]] = shl i32 [[X_CURR]], 1, [[DBG172:!dbg !.*]]
+; ALL-NEXT: call void @llvm.dbg.value(metadata i32 [[X_NEXT]], [[META166:metadata !.*]], metadata !DIExpression()), [[DBG172]]
+; ALL-NEXT: br i1 [[X_CURR_ISBITUNSET]], label [[END:%.*]], label [[LOOP]], [[DBG173:!dbg !.*]]
+; ALL: end:
+; ALL-NEXT: [[X_CURR_LCSSA:%.*]] = phi i32 [ [[X_CURR]], [[LOOP]] ], [[DBG169]]
+; ALL-NEXT: call void @llvm.dbg.value(metadata i32 [[X_CURR_LCSSA]], [[META163]], metadata !DIExpression()), [[DBG169]]
+; ALL-NEXT: ret i32 [[X_CURR_LCSSA]], [[DBG174:!dbg !.*]]
+;
+entry:
+ %bitmask = shl i32 1, %bit
+ br label %loop
+
+loop:
+ %x.curr = phi i32 [ %x, %entry ], [ %x.next, %loop ]
+ %x.curr.bitmasked = and i32 %x.curr, %bitmask
+ %x.curr.isbitunset = icmp eq i32 %x.curr.bitmasked, 0
+ %x.next = shl i32 %x.curr, 1
+ br i1 %x.curr.isbitunset, label %end, label %loop ; wrong order of successors
+
+end:
+ ret i32 %x.curr
+}
+
+; We should loop while %x.curr.bitmasked is 0, not while it is not 0.
+define i32 @n10(i32 %x, i32 %bit) {
+; ALL-LABEL: @n10(
+; ALL-NEXT: entry:
+; ALL-NEXT: [[BITMASK:%.*]] = shl i32 1, [[BIT:%.*]], [[DBG182:!dbg !.*]]
+; ALL-NEXT: call void @llvm.dbg.value(metadata i32 [[BITMASK]], [[META177:metadata !.*]], metadata !DIExpression()), [[DBG182]]
+; ALL-NEXT: br label [[LOOP:%.*]], [[DBG183:!dbg !.*]]
+; ALL: loop:
+; ALL-NEXT: [[X_CURR:%.*]] = phi i32 [ [[X:%.*]], [[ENTRY:%.*]] ], [ [[X_NEXT:%.*]], [[LOOP]] ], [[DBG184:!dbg !.*]]
+; ALL-NEXT: call void @llvm.dbg.value(metadata i32 [[X_CURR]], [[META178:metadata !.*]], metadata !DIExpression()), [[DBG184]]
+; ALL-NEXT: [[X_CURR_BITMASKED:%.*]] = and i32 [[X_CURR]], [[BITMASK]], [[DBG185:!dbg !.*]]
+; ALL-NEXT: call void @llvm.dbg.value(metadata i32 [[X_CURR_BITMASKED]], [[META179:metadata !.*]], metadata !DIExpression()), [[DBG185]]
+; ALL-NEXT: [[X_CURR_ISBITUNSET:%.*]] = icmp ne i32 [[X_CURR_BITMASKED]], 0, [[DBG186:!dbg !.*]]
+; ALL-NEXT: call void @llvm.dbg.value(metadata i1 [[X_CURR_ISBITUNSET]], [[META180:metadata !.*]], metadata !DIExpression()), [[DBG186]]
+; ALL-NEXT: [[X_NEXT]] = shl i32 [[X_CURR]], 1, [[DBG187:!dbg !.*]]
+; ALL-NEXT: call void @llvm.dbg.value(metadata i32 [[X_NEXT]], [[META181:metadata !.*]], metadata !DIExpression()), [[DBG187]]
+; ALL-NEXT: br i1 [[X_CURR_ISBITUNSET]], label [[LOOP]], label [[END:%.*]], [[DBG188:!dbg !.*]]
+; ALL: end:
+; ALL-NEXT: [[X_CURR_LCSSA:%.*]] = phi i32 [ [[X_CURR]], [[LOOP]] ], [[DBG184]]
+; ALL-NEXT: call void @llvm.dbg.value(metadata i32 [[X_CURR_LCSSA]], [[META178]], metadata !DIExpression()), [[DBG184]]
+; ALL-NEXT: ret i32 [[X_CURR_LCSSA]], [[DBG189:!dbg !.*]]
+;
+entry:
+ %bitmask = shl i32 1, %bit
+ br label %loop
+
+loop:
+ %x.curr = phi i32 [ %x, %entry ], [ %x.next, %loop ]
+ %x.curr.bitmasked = and i32 %x.curr, %bitmask
+ %x.curr.isbitunset = icmp ne i32 %x.curr.bitmasked, 0 ; wrong predicate
+ %x.next = shl i32 %x.curr, 1
+ br i1 %x.curr.isbitunset, label %loop, label %end
+
+end:
+ ret i32 %x.curr
+}
+
+; PHI node is not a recurrence
+define i32 @n11(i32 %x, i32 %bit) {
+; ALL-LABEL: @n11(
+; ALL-NEXT: entry:
+; ALL-NEXT: [[BITMASK:%.*]] = shl i32 1, [[BIT:%.*]], [[DBG197:!dbg !.*]]
+; ALL-NEXT: call void @llvm.dbg.value(metadata i32 [[BITMASK]], [[META192:metadata !.*]], metadata !DIExpression()), [[DBG197]]
+; ALL-NEXT: br label [[LOOP:%.*]], [[DBG198:!dbg !.*]]
+; ALL: loop:
+; ALL-NEXT: call void @llvm.dbg.value(metadata i32 [[X:%.*]], [[META193:metadata !.*]], metadata !DIExpression()), [[DBG199:!dbg !.*]]
+; ALL-NEXT: [[X_CURR_BITMASKED:%.*]] = and i32 [[X]], [[BITMASK]], [[DBG200:!dbg !.*]]
+; ALL-NEXT: call void @llvm.dbg.value(metadata i32 [[X_CURR_BITMASKED]], [[META194:metadata !.*]], metadata !DIExpression()), [[DBG200]]
+; ALL-NEXT: [[X_CURR_ISBITUNSET:%.*]] = icmp eq i32 [[X_CURR_BITMASKED]], 0, [[DBG201:!dbg !.*]]
+; ALL-NEXT: call void @llvm.dbg.value(metadata i1 [[X_CURR_ISBITUNSET]], [[META195:metadata !.*]], metadata !DIExpression()), [[DBG201]]
+; ALL-NEXT: [[X_NEXT:%.*]] = shl i32 [[X]], 1, [[DBG202:!dbg !.*]]
+; ALL-NEXT: call void @llvm.dbg.value(metadata i32 [[X_NEXT]], [[META196:metadata !.*]], metadata !DIExpression()), [[DBG202]]
+; ALL-NEXT: br i1 [[X_CURR_ISBITUNSET]], label [[LOOP]], label [[END:%.*]], [[DBG203:!dbg !.*]]
+; ALL: end:
+; ALL-NEXT: ret i32 [[X]], [[DBG204:!dbg !.*]]
+;
+entry:
+ %bitmask = shl i32 1, %bit
+ br label %loop
+
+loop:
+ %x.curr = phi i32 [ %x, %entry ], [ %x, %loop ] ; should use %x.next when coming from %loop
+ %x.curr.bitmasked = and i32 %x.curr, %bitmask
+ %x.curr.isbitunset = icmp eq i32 %x.curr.bitmasked, 0
+ %x.next = shl i32 %x.curr, 1
+ br i1 %x.curr.isbitunset, label %loop, label %end
+
+end:
+ ret i32 %x.curr
+}
+
+; Masking wrong value
+define i32 @n12(i32 %x, i32 %bit) {
+; ALL-LABEL: @n12(
+; ALL-NEXT: entry:
+; ALL-NEXT: [[BITMASK:%.*]] = shl i32 1, [[BIT:%.*]], [[DBG212:!dbg !.*]]
+; ALL-NEXT: call void @llvm.dbg.value(metadata i32 [[BITMASK]], [[META207:metadata !.*]], metadata !DIExpression()), [[DBG212]]
+; ALL-NEXT: br label [[LOOP:%.*]], [[DBG213:!dbg !.*]]
+; ALL: loop:
+; ALL-NEXT: [[X_CURR:%.*]] = phi i32 [ [[X:%.*]], [[ENTRY:%.*]] ], [ [[X_NEXT:%.*]], [[LOOP]] ], [[DBG214:!dbg !.*]]
+; ALL-NEXT: call void @llvm.dbg.value(metadata i32 [[X_CURR]], [[META208:metadata !.*]], metadata !DIExpression()), [[DBG214]]
+; ALL-NEXT: [[X_CURR_BITMASKED:%.*]] = and i32 [[X]], [[BITMASK]], [[DBG215:!dbg !.*]]
+; ALL-NEXT: call void @llvm.dbg.value(metadata i32 [[X_CURR_BITMASKED]], [[META209:metadata !.*]], metadata !DIExpression()), [[DBG215]]
+; ALL-NEXT: [[X_CURR_ISBITUNSET:%.*]] = icmp eq i32 [[X_CURR_BITMASKED]], 0, [[DBG216:!dbg !.*]]
+; ALL-NEXT: call void @llvm.dbg.value(metadata i1 [[X_CURR_ISBITUNSET]], [[META210:metadata !.*]], metadata !DIExpression()), [[DBG216]]
+; ALL-NEXT: [[X_NEXT]] = shl i32 [[X_CURR]], 1, [[DBG217:!dbg !.*]]
+; ALL-NEXT: call void @llvm.dbg.value(metadata i32 [[X_NEXT]], [[META211:metadata !.*]], metadata !DIExpression()), [[DBG217]]
+; ALL-NEXT: br i1 [[X_CURR_ISBITUNSET]], label [[LOOP]], label [[END:%.*]], [[DBG218:!dbg !.*]]
+; ALL: end:
+; ALL-NEXT: [[X_CURR_LCSSA:%.*]] = phi i32 [ [[X_CURR]], [[LOOP]] ], [[DBG214]]
+; ALL-NEXT: call void @llvm.dbg.value(metadata i32 [[X_CURR_LCSSA]], [[META208]], metadata !DIExpression()), [[DBG214]]
+; ALL-NEXT: ret i32 [[X_CURR_LCSSA]], [[DBG219:!dbg !.*]]
+;
+entry:
+ %bitmask = shl i32 1, %bit
+ br label %loop
+
+loop:
+ %x.curr = phi i32 [ %x, %entry ], [ %x.next, %loop ]
+ %x.curr.bitmasked = and i32 %x, %bitmask ; should use %x.curr, not %x
+ %x.curr.isbitunset = icmp eq i32 %x.curr.bitmasked, 0
+ %x.next = shl i32 %x.curr, 1
+ br i1 %x.curr.isbitunset, label %loop, label %end
+
+end:
+ ret i32 %x.curr
+}
+
+; Checking wrong value
+define i32 @n13(i32 %x, i32 %bit) {
+; ALL-LABEL: @n13(
+; ALL-NEXT: entry:
+; ALL-NEXT: [[BITMASK:%.*]] = shl i32 1, [[BIT:%.*]], [[DBG227:!dbg !.*]]
+; ALL-NEXT: call void @llvm.dbg.value(metadata i32 [[BITMASK]], [[META222:metadata !.*]], metadata !DIExpression()), [[DBG227]]
+; ALL-NEXT: br label [[LOOP:%.*]], [[DBG228:!dbg !.*]]
+; ALL: loop:
+; ALL-NEXT: [[X_CURR:%.*]] = phi i32 [ [[X:%.*]], [[ENTRY:%.*]] ], [ [[X_NEXT:%.*]], [[LOOP]] ], [[DBG229:!dbg !.*]]
+; ALL-NEXT: call void @llvm.dbg.value(metadata i32 [[X_CURR]], [[META223:metadata !.*]], metadata !DIExpression()), [[DBG229]]
+; ALL-NEXT: [[X_CURR_BITMASKED:%.*]] = and i32 [[X_CURR]], [[BITMASK]], [[DBG230:!dbg !.*]]
+; ALL-NEXT: call void @llvm.dbg.value(metadata i32 [[X_CURR_BITMASKED]], [[META224:metadata !.*]], metadata !DIExpression()), [[DBG230]]
+; ALL-NEXT: [[X_CURR_ISBITUNSET:%.*]] = icmp eq i32 [[X_CURR]], 0, [[DBG231:!dbg !.*]]
+; ALL-NEXT: call void @llvm.dbg.value(metadata i1 [[X_CURR_ISBITUNSET]], [[META225:metadata !.*]], metadata !DIExpression()), [[DBG231]]
+; ALL-NEXT: [[X_NEXT]] = shl i32 [[X_CURR]], 1, [[DBG232:!dbg !.*]]
+; ALL-NEXT: call void @llvm.dbg.value(metadata i32 [[X_NEXT]], [[META226:metadata !.*]], metadata !DIExpression()), [[DBG232]]
+; ALL-NEXT: br i1 [[X_CURR_ISBITUNSET]], label [[LOOP]], label [[END:%.*]], [[DBG233:!dbg !.*]]
+; ALL: end:
+; ALL-NEXT: [[X_CURR_LCSSA:%.*]] = phi i32 [ [[X_CURR]], [[LOOP]] ], [[DBG229]]
+; ALL-NEXT: call void @llvm.dbg.value(metadata i32 [[X_CURR_LCSSA]], [[META223]], metadata !DIExpression()), [[DBG229]]
+; ALL-NEXT: ret i32 [[X_CURR_LCSSA]], [[DBG234:!dbg !.*]]
+;
+entry:
+ %bitmask = shl i32 1, %bit
+ br label %loop
+
+loop:
+ %x.curr = phi i32 [ %x, %entry ], [ %x.next, %loop ]
+ %x.curr.bitmasked = and i32 %x.curr, %bitmask
+ %x.curr.isbitunset = icmp eq i32 %x.curr, 0 ; should be checking %x.curr.bitmasked
+ %x.next = shl i32 %x.curr, 1
+ br i1 %x.curr.isbitunset, label %loop, label %end
+
+end:
+ ret i32 %x.curr
+}
+
+define i32 @n14(i32 %x, i32 %bit) {
+; ALL-LABEL: @n14(
+; ALL-NEXT: entry:
+; ALL-NEXT: [[BITMASK:%.*]] = shl i32 1, [[BIT:%.*]], [[DBG242:!dbg !.*]]
+; ALL-NEXT: call void @llvm.dbg.value(metadata i32 [[BITMASK]], [[META237:metadata !.*]], metadata !DIExpression()), [[DBG242]]
+; ALL-NEXT: br label [[LOOP:%.*]], [[DBG243:!dbg !.*]]
+; ALL: loop:
+; ALL-NEXT: [[X_CURR:%.*]] = phi i32 [ [[X:%.*]], [[ENTRY:%.*]] ], [ [[X_NEXT:%.*]], [[LOOP]] ], [[DBG244:!dbg !.*]]
+; ALL-NEXT: call void @llvm.dbg.value(metadata i32 [[X_CURR]], [[META238:metadata !.*]], metadata !DIExpression()), [[DBG244]]
+; ALL-NEXT: [[X_CURR_BITMASKED:%.*]] = and i32 [[X_CURR]], [[BITMASK]], [[DBG245:!dbg !.*]]
+; ALL-NEXT: call void @llvm.dbg.value(metadata i32 [[X_CURR_BITMASKED]], [[META239:metadata !.*]], metadata !DIExpression()), [[DBG245]]
+; ALL-NEXT: [[X_CURR_ISBITUNSET:%.*]] = icmp eq i32 [[X_CURR_BITMASKED]], 0, [[DBG246:!dbg !.*]]
+; ALL-NEXT: call void @llvm.dbg.value(metadata i1 [[X_CURR_ISBITUNSET]], [[META240:metadata !.*]], metadata !DIExpression()), [[DBG246]]
+; ALL-NEXT: [[X_NEXT]] = shl i32 [[X]], 1, [[DBG247:!dbg !.*]]
+; ALL-NEXT: call void @llvm.dbg.value(metadata i32 [[X_NEXT]], [[META241:metadata !.*]], metadata !DIExpression()), [[DBG247]]
+; ALL-NEXT: br i1 [[X_CURR_ISBITUNSET]], label [[LOOP]], label [[END:%.*]], [[DBG248:!dbg !.*]]
+; ALL: end:
+; ALL-NEXT: [[X_CURR_LCSSA:%.*]] = phi i32 [ [[X_CURR]], [[LOOP]] ], [[DBG244]]
+; ALL-NEXT: call void @llvm.dbg.value(metadata i32 [[X_CURR_LCSSA]], [[META238]], metadata !DIExpression()), [[DBG244]]
+; ALL-NEXT: ret i32 [[X_CURR_LCSSA]], [[DBG249:!dbg !.*]]
+;
+entry:
+ %bitmask = shl i32 1, %bit
+ br label %loop
+
+loop:
+ %x.curr = phi i32 [ %x, %entry ], [ %x.next, %loop ]
+ %x.curr.bitmasked = and i32 %x.curr, %bitmask
+ %x.curr.isbitunset = icmp eq i32 %x.curr.bitmasked, 0
+ %x.next = shl i32 %x, 1 ; should be shifting %x.curr
+ br i1 %x.curr.isbitunset, label %loop, label %end
+
+end:
+ ret i32 %x.curr
+}
+
+;-------------------------------------------------------------------------------
+; Tests with extra cruft.
+
+; If loop body has any extra instructions we don't want to deal with it.
+define i32 @n15(i32 %x, i32 %bit) {
+; ALL-LABEL: @n15(
+; ALL-NEXT: entry:
+; ALL-NEXT: [[BITMASK:%.*]] = shl i32 1, [[BIT:%.*]], [[DBG257:!dbg !.*]]
+; ALL-NEXT: call void @llvm.dbg.value(metadata i32 [[BITMASK]], [[META252:metadata !.*]], metadata !DIExpression()), [[DBG257]]
+; ALL-NEXT: br label [[LOOP:%.*]], [[DBG258:!dbg !.*]]
+; ALL: loop:
+; ALL-NEXT: [[X_CURR:%.*]] = phi i32 [ [[X:%.*]], [[ENTRY:%.*]] ], [ [[X_NEXT:%.*]], [[LOOP]] ], [[DBG259:!dbg !.*]]
+; ALL-NEXT: call void @llvm.dbg.value(metadata i32 [[X_CURR]], [[META253:metadata !.*]], metadata !DIExpression()), [[DBG259]]
+; ALL-NEXT: call void @external_side_effect(), [[DBG260:!dbg !.*]]
+; ALL-NEXT: [[X_CURR_BITMASKED:%.*]] = and i32 [[X_CURR]], [[BITMASK]], [[DBG261:!dbg !.*]]
+; ALL-NEXT: call void @llvm.dbg.value(metadata i32 [[X_CURR_BITMASKED]], [[META254:metadata !.*]], metadata !DIExpression()), [[DBG261]]
+; ALL-NEXT: [[X_CURR_ISBITUNSET:%.*]] = icmp eq i32 [[X_CURR_BITMASKED]], 0, [[DBG262:!dbg !.*]]
+; ALL-NEXT: call void @llvm.dbg.value(metadata i1 [[X_CURR_ISBITUNSET]], [[META255:metadata !.*]], metadata !DIExpression()), [[DBG262]]
+; ALL-NEXT: [[X_NEXT]] = shl i32 [[X_CURR]], 1, [[DBG263:!dbg !.*]]
+; ALL-NEXT: call void @llvm.dbg.value(metadata i32 [[X_NEXT]], [[META256:metadata !.*]], metadata !DIExpression()), [[DBG263]]
+; ALL-NEXT: br i1 [[X_CURR_ISBITUNSET]], label [[LOOP]], label [[END:%.*]], [[DBG264:!dbg !.*]]
+; ALL: end:
+; ALL-NEXT: [[X_CURR_LCSSA:%.*]] = phi i32 [ [[X_CURR]], [[LOOP]] ], [[DBG259]]
+; ALL-NEXT: call void @llvm.dbg.value(metadata i32 [[X_CURR_LCSSA]], [[META253]], metadata !DIExpression()), [[DBG259]]
+; ALL-NEXT: ret i32 [[X_CURR_LCSSA]], [[DBG265:!dbg !.*]]
+;
+entry:
+ %bitmask = shl i32 1, %bit
+ br label %loop
+
+loop:
+ %x.curr = phi i32 [ %x, %entry ], [ %x.next, %loop ]
+ call void @external_side_effect() ; not part of idiom.
+ %x.curr.bitmasked = and i32 %x.curr, %bitmask
+ %x.curr.isbitunset = icmp eq i32 %x.curr.bitmasked, 0
+ %x.next = shl i32 %x.curr, 1
+ br i1 %x.curr.isbitunset, label %loop, label %end
+
+end:
+ ret i32 %x.curr
+}
+
+; In-loop instructions should not have uses outside of the loop.
+define i32 @n16(i32 %x, i32 %bit) {
+; ALL-LABEL: @n16(
+; ALL-NEXT: entry:
+; ALL-NEXT: [[BITMASK:%.*]] = shl i32 1, [[BIT:%.*]], [[DBG273:!dbg !.*]]
+; ALL-NEXT: call void @llvm.dbg.value(metadata i32 [[BITMASK]], [[META268:metadata !.*]], metadata !DIExpression()), [[DBG273]]
+; ALL-NEXT: br label [[LOOP:%.*]], [[DBG274:!dbg !.*]]
+; ALL: loop:
+; ALL-NEXT: [[X_CURR:%.*]] = phi i32 [ [[X:%.*]], [[ENTRY:%.*]] ], [ [[X_NEXT:%.*]], [[LOOP]] ], [[DBG275:!dbg !.*]]
+; ALL-NEXT: call void @llvm.dbg.value(metadata i32 [[X_CURR]], [[META269:metadata !.*]], metadata !DIExpression()), [[DBG275]]
+; ALL-NEXT: [[X_CURR_BITMASKED:%.*]] = and i32 [[X_CURR]], [[BITMASK]], [[DBG276:!dbg !.*]]
+; ALL-NEXT: call void @llvm.dbg.value(metadata i32 [[X_CURR_BITMASKED]], [[META270:metadata !.*]], metadata !DIExpression()), [[DBG276]]
+; ALL-NEXT: [[X_CURR_ISBITUNSET:%.*]] = icmp eq i32 [[X_CURR_BITMASKED]], 0, [[DBG277:!dbg !.*]]
+; ALL-NEXT: call void @llvm.dbg.value(metadata i1 [[X_CURR_ISBITUNSET]], [[META271:metadata !.*]], metadata !DIExpression()), [[DBG277]]
+; ALL-NEXT: [[X_NEXT]] = shl i32 [[X_CURR]], 1, [[DBG278:!dbg !.*]]
+; ALL-NEXT: call void @llvm.dbg.value(metadata i32 [[X_NEXT]], [[META272:metadata !.*]], metadata !DIExpression()), [[DBG278]]
+; ALL-NEXT: br i1 [[X_CURR_ISBITUNSET]], label [[LOOP]], label [[END:%.*]], [[DBG279:!dbg !.*]]
+; ALL: end:
+; ALL-NEXT: [[X_CURR_LCSSA:%.*]] = phi i32 [ [[X_CURR]], [[LOOP]] ], [[DBG275]]
+; ALL-NEXT: [[X_CURR_BITMASKED_LCSSA:%.*]] = phi i32 [ [[X_CURR_BITMASKED]], [[LOOP]] ], [[DBG276]]
+; ALL-NEXT: call void @llvm.dbg.value(metadata i32 [[X_CURR_LCSSA]], [[META269]], metadata !DIExpression()), [[DBG275]]
+; ALL-NEXT: call void @use32(i32 [[X_CURR_BITMASKED_LCSSA]]), [[DBG280:!dbg !.*]]
+; ALL-NEXT: ret i32 [[X_CURR_LCSSA]], [[DBG281:!dbg !.*]]
+;
+entry:
+ %bitmask = shl i32 1, %bit
+ br label %loop
+
+loop:
+ %x.curr = phi i32 [ %x, %entry ], [ %x.next, %loop ]
+ %x.curr.bitmasked = and i32 %x.curr, %bitmask
+ %x.curr.isbitunset = icmp eq i32 %x.curr.bitmasked, 0
+ %x.next = shl i32 %x.curr, 1
+ br i1 %x.curr.isbitunset, label %loop, label %end
+
+end:
+ call void @use32(i32 %x.curr.bitmasked)
+ ret i32 %x.curr
+}
+define i32 @n17(i32 %x, i32 %bit) {
+; ALL-LABEL: @n17(
+; ALL-NEXT: entry:
+; ALL-NEXT: [[BITMASK:%.*]] = shl i32 1, [[BIT:%.*]], [[DBG289:!dbg !.*]]
+; ALL-NEXT: call void @llvm.dbg.value(metadata i32 [[BITMASK]], [[META284:metadata !.*]], metadata !DIExpression()), [[DBG289]]
+; ALL-NEXT: br label [[LOOP:%.*]], [[DBG290:!dbg !.*]]
+; ALL: loop:
+; ALL-NEXT: [[X_CURR:%.*]] = phi i32 [ [[X:%.*]], [[ENTRY:%.*]] ], [ [[X_NEXT:%.*]], [[LOOP]] ], [[DBG291:!dbg !.*]]
+; ALL-NEXT: call void @llvm.dbg.value(metadata i32 [[X_CURR]], [[META285:metadata !.*]], metadata !DIExpression()), [[DBG291]]
+; ALL-NEXT: [[X_CURR_BITMASKED:%.*]] = and i32 [[X_CURR]], [[BITMASK]], [[DBG292:!dbg !.*]]
+; ALL-NEXT: call void @llvm.dbg.value(metadata i32 [[X_CURR_BITMASKED]], [[META286:metadata !.*]], metadata !DIExpression()), [[DBG292]]
+; ALL-NEXT: [[X_CURR_ISBITUNSET:%.*]] = icmp eq i32 [[X_CURR_BITMASKED]], 0, [[DBG293:!dbg !.*]]
+; ALL-NEXT: call void @llvm.dbg.value(metadata i1 [[X_CURR_ISBITUNSET]], [[META287:metadata !.*]], metadata !DIExpression()), [[DBG293]]
+; ALL-NEXT: [[X_NEXT]] = shl i32 [[X_CURR]], 1, [[DBG294:!dbg !.*]]
+; ALL-NEXT: call void @llvm.dbg.value(metadata i32 [[X_NEXT]], [[META288:metadata !.*]], metadata !DIExpression()), [[DBG294]]
+; ALL-NEXT: br i1 [[X_CURR_ISBITUNSET]], label [[LOOP]], label [[END:%.*]], [[DBG295:!dbg !.*]]
+; ALL: end:
+; ALL-NEXT: [[X_CURR_LCSSA:%.*]] = phi i32 [ [[X_CURR]], [[LOOP]] ], [[DBG291]]
+; ALL-NEXT: [[X_CURR_ISBITUNSET_LCSSA:%.*]] = phi i1 [ [[X_CURR_ISBITUNSET]], [[LOOP]] ], [[DBG293]]
+; ALL-NEXT: call void @llvm.dbg.value(metadata i32 [[X_CURR_LCSSA]], [[META285]], metadata !DIExpression()), [[DBG291]]
+; ALL-NEXT: call void @use1(i1 [[X_CURR_ISBITUNSET_LCSSA]]), [[DBG296:!dbg !.*]]
+; ALL-NEXT: ret i32 [[X_CURR_LCSSA]], [[DBG297:!dbg !.*]]
+;
+entry:
+ %bitmask = shl i32 1, %bit
+ br label %loop
+
+loop:
+ %x.curr = phi i32 [ %x, %entry ], [ %x.next, %loop ]
+ %x.curr.bitmasked = and i32 %x.curr, %bitmask
+ %x.curr.isbitunset = icmp eq i32 %x.curr.bitmasked, 0
+ %x.next = shl i32 %x.curr, 1
+ br i1 %x.curr.isbitunset, label %loop, label %end
+
+end:
+ call void @use1(i1 %x.curr.isbitunset)
+ ret i32 %x.curr
+}
+define i32 @n18(i32 %x, i32 %bit) {
+; ALL-LABEL: @n18(
+; ALL-NEXT: entry:
+; ALL-NEXT: [[BITMASK:%.*]] = shl i32 1, [[BIT:%.*]], [[DBG305:!dbg !.*]]
+; ALL-NEXT: call void @llvm.dbg.value(metadata i32 [[BITMASK]], [[META300:metadata !.*]], metadata !DIExpression()), [[DBG305]]
+; ALL-NEXT: br label [[LOOP:%.*]], [[DBG306:!dbg !.*]]
+; ALL: loop:
+; ALL-NEXT: [[X_CURR:%.*]] = phi i32 [ [[X:%.*]], [[ENTRY:%.*]] ], [ [[X_NEXT:%.*]], [[LOOP]] ], [[DBG307:!dbg !.*]]
+; ALL-NEXT: call void @llvm.dbg.value(metadata i32 [[X_CURR]], [[META301:metadata !.*]], metadata !DIExpression()), [[DBG307]]
+; ALL-NEXT: [[X_CURR_BITMASKED:%.*]] = and i32 [[X_CURR]], [[BITMASK]], [[DBG308:!dbg !.*]]
+; ALL-NEXT: call void @llvm.dbg.value(metadata i32 [[X_CURR_BITMASKED]], [[META302:metadata !.*]], metadata !DIExpression()), [[DBG308]]
+; ALL-NEXT: [[X_CURR_ISBITUNSET:%.*]] = icmp eq i32 [[X_CURR_BITMASKED]], 0, [[DBG309:!dbg !.*]]
+; ALL-NEXT: call void @llvm.dbg.value(metadata i1 [[X_CURR_ISBITUNSET]], [[META303:metadata !.*]], metadata !DIExpression()), [[DBG309]]
+; ALL-NEXT: [[X_NEXT]] = shl i32 [[X_CURR]], 1, [[DBG310:!dbg !.*]]
+; ALL-NEXT: call void @llvm.dbg.value(metadata i32 [[X_NEXT]], [[META304:metadata !.*]], metadata !DIExpression()), [[DBG310]]
+; ALL-NEXT: br i1 [[X_CURR_ISBITUNSET]], label [[LOOP]], label [[END:%.*]], [[DBG311:!dbg !.*]]
+; ALL: end:
+; ALL-NEXT: [[X_CURR_LCSSA:%.*]] = phi i32 [ [[X_CURR]], [[LOOP]] ], [[DBG307]]
+; ALL-NEXT: [[X_NEXT_LCSSA:%.*]] = phi i32 [ [[X_NEXT]], [[LOOP]] ], [[DBG310]]
+; ALL-NEXT: call void @llvm.dbg.value(metadata i32 [[X_CURR_LCSSA]], [[META301]], metadata !DIExpression()), [[DBG307]]
+; ALL-NEXT: call void @use32(i32 [[X_NEXT_LCSSA]]), [[DBG312:!dbg !.*]]
+; ALL-NEXT: ret i32 [[X_CURR_LCSSA]], [[DBG313:!dbg !.*]]
+;
+entry:
+ %bitmask = shl i32 1, %bit
+ br label %loop
+
+loop:
+ %x.curr = phi i32 [ %x, %entry ], [ %x.next, %loop ]
+ %x.curr.bitmasked = and i32 %x.curr, %bitmask
+ %x.curr.isbitunset = icmp eq i32 %x.curr.bitmasked, 0
+ %x.next = shl i32 %x.curr, 1
+ br i1 %x.curr.isbitunset, label %loop, label %end
+
+end:
+ call void @use32(i32 %x.next)
+ ret i32 %x.curr
+}
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