| ; NOTE: Assertions have been autogenerated by utils/update_test_checks.py |
| ; RUN: opt -loop-idiom -mtriple=x86_64 -mcpu=core-avx2 < %s -S | FileCheck %s -check-prefixes=ALL,LZCNT |
| ; RUN: opt -loop-idiom -mtriple=x86_64 -mcpu=corei7 < %s -S | FileCheck %s -check-prefixes=ALL,NOLZCNT |
| |
| ; Recognize CTLZ builtin pattern. |
| ; Here we'll just convert loop to countable, |
| ; so do not insert builtin if CPU do not support CTLZ |
| ; |
| ; int ctlz_and_other(int n, char *a) |
| ; { |
| ; n = n >= 0 ? n : -n; |
| ; int i = 0, n0 = n; |
| ; while(n >>= 1) { |
| ; a[i] = (n0 & (1 << i)) ? 1 : 0; |
| ; i++; |
| ; } |
| ; return i; |
| ; } |
| ; |
| define i32 @ctlz_and_other(i32 %n, i8* nocapture %a) { |
| ; LZCNT-LABEL: @ctlz_and_other( |
| ; LZCNT-NEXT: entry: |
| ; LZCNT-NEXT: [[C:%.*]] = icmp sgt i32 [[N:%.*]], 0 |
| ; LZCNT-NEXT: [[NEGN:%.*]] = sub nsw i32 0, [[N]] |
| ; LZCNT-NEXT: [[ABS_N:%.*]] = select i1 [[C]], i32 [[N]], i32 [[NEGN]] |
| ; LZCNT-NEXT: [[SHR8:%.*]] = lshr i32 [[ABS_N]], 1 |
| ; LZCNT-NEXT: [[TOBOOL9:%.*]] = icmp eq i32 [[SHR8]], 0 |
| ; LZCNT-NEXT: br i1 [[TOBOOL9]], label [[WHILE_END:%.*]], label [[WHILE_BODY_PREHEADER:%.*]] |
| ; LZCNT: while.body.preheader: |
| ; LZCNT-NEXT: [[TMP0:%.*]] = call i32 @llvm.ctlz.i32(i32 [[SHR8]], i1 true) |
| ; LZCNT-NEXT: [[TMP1:%.*]] = sub i32 32, [[TMP0]] |
| ; LZCNT-NEXT: [[TMP2:%.*]] = zext i32 [[TMP1]] to i64 |
| ; LZCNT-NEXT: br label [[WHILE_BODY:%.*]] |
| ; LZCNT: while.body: |
| ; LZCNT-NEXT: [[TCPHI:%.*]] = phi i32 [ [[TMP1]], [[WHILE_BODY_PREHEADER]] ], [ [[TCDEC:%.*]], [[WHILE_BODY]] ] |
| ; LZCNT-NEXT: [[INDVARS_IV:%.*]] = phi i64 [ [[INDVARS_IV_NEXT:%.*]], [[WHILE_BODY]] ], [ 0, [[WHILE_BODY_PREHEADER]] ] |
| ; LZCNT-NEXT: [[SHR11:%.*]] = phi i32 [ [[SHR:%.*]], [[WHILE_BODY]] ], [ [[SHR8]], [[WHILE_BODY_PREHEADER]] ] |
| ; LZCNT-NEXT: [[TMP3:%.*]] = trunc i64 [[INDVARS_IV]] to i32 |
| ; LZCNT-NEXT: [[SHL:%.*]] = shl i32 1, [[TMP3]] |
| ; LZCNT-NEXT: [[AND:%.*]] = and i32 [[SHL]], [[ABS_N]] |
| ; LZCNT-NEXT: [[TOBOOL1:%.*]] = icmp ne i32 [[AND]], 0 |
| ; LZCNT-NEXT: [[CONV:%.*]] = zext i1 [[TOBOOL1]] to i8 |
| ; LZCNT-NEXT: [[ARRAYIDX:%.*]] = getelementptr inbounds i8, i8* [[A:%.*]], i64 [[INDVARS_IV]] |
| ; LZCNT-NEXT: store i8 [[CONV]], i8* [[ARRAYIDX]], align 1 |
| ; LZCNT-NEXT: [[INDVARS_IV_NEXT]] = add nuw i64 [[INDVARS_IV]], 1 |
| ; LZCNT-NEXT: [[SHR]] = ashr i32 [[SHR11]], 1 |
| ; LZCNT-NEXT: [[TCDEC]] = sub nsw i32 [[TCPHI]], 1 |
| ; LZCNT-NEXT: [[TOBOOL:%.*]] = icmp eq i32 [[TCDEC]], 0 |
| ; LZCNT-NEXT: br i1 [[TOBOOL]], label [[WHILE_END_LOOPEXIT:%.*]], label [[WHILE_BODY]] |
| ; LZCNT: while.end.loopexit: |
| ; LZCNT-NEXT: [[INDVARS_IV_NEXT_LCSSA:%.*]] = phi i64 [ [[TMP2]], [[WHILE_BODY]] ] |
| ; LZCNT-NEXT: [[TMP4:%.*]] = trunc i64 [[INDVARS_IV_NEXT_LCSSA]] to i32 |
| ; LZCNT-NEXT: br label [[WHILE_END]] |
| ; LZCNT: while.end: |
| ; LZCNT-NEXT: [[I_0_LCSSA:%.*]] = phi i32 [ 0, [[ENTRY:%.*]] ], [ [[TMP4]], [[WHILE_END_LOOPEXIT]] ] |
| ; LZCNT-NEXT: ret i32 [[I_0_LCSSA]] |
| ; |
| ; NOLZCNT-LABEL: @ctlz_and_other( |
| ; NOLZCNT-NEXT: entry: |
| ; NOLZCNT-NEXT: [[C:%.*]] = icmp sgt i32 [[N:%.*]], 0 |
| ; NOLZCNT-NEXT: [[NEGN:%.*]] = sub nsw i32 0, [[N]] |
| ; NOLZCNT-NEXT: [[ABS_N:%.*]] = select i1 [[C]], i32 [[N]], i32 [[NEGN]] |
| ; NOLZCNT-NEXT: [[SHR8:%.*]] = lshr i32 [[ABS_N]], 1 |
| ; NOLZCNT-NEXT: [[TOBOOL9:%.*]] = icmp eq i32 [[SHR8]], 0 |
| ; NOLZCNT-NEXT: br i1 [[TOBOOL9]], label [[WHILE_END:%.*]], label [[WHILE_BODY_PREHEADER:%.*]] |
| ; NOLZCNT: while.body.preheader: |
| ; NOLZCNT-NEXT: br label [[WHILE_BODY:%.*]] |
| ; NOLZCNT: while.body: |
| ; NOLZCNT-NEXT: [[INDVARS_IV:%.*]] = phi i64 [ [[INDVARS_IV_NEXT:%.*]], [[WHILE_BODY]] ], [ 0, [[WHILE_BODY_PREHEADER]] ] |
| ; NOLZCNT-NEXT: [[SHR11:%.*]] = phi i32 [ [[SHR:%.*]], [[WHILE_BODY]] ], [ [[SHR8]], [[WHILE_BODY_PREHEADER]] ] |
| ; NOLZCNT-NEXT: [[TMP0:%.*]] = trunc i64 [[INDVARS_IV]] to i32 |
| ; NOLZCNT-NEXT: [[SHL:%.*]] = shl i32 1, [[TMP0]] |
| ; NOLZCNT-NEXT: [[AND:%.*]] = and i32 [[SHL]], [[ABS_N]] |
| ; NOLZCNT-NEXT: [[TOBOOL1:%.*]] = icmp ne i32 [[AND]], 0 |
| ; NOLZCNT-NEXT: [[CONV:%.*]] = zext i1 [[TOBOOL1]] to i8 |
| ; NOLZCNT-NEXT: [[ARRAYIDX:%.*]] = getelementptr inbounds i8, i8* [[A:%.*]], i64 [[INDVARS_IV]] |
| ; NOLZCNT-NEXT: store i8 [[CONV]], i8* [[ARRAYIDX]], align 1 |
| ; NOLZCNT-NEXT: [[INDVARS_IV_NEXT]] = add nuw i64 [[INDVARS_IV]], 1 |
| ; NOLZCNT-NEXT: [[SHR]] = ashr i32 [[SHR11]], 1 |
| ; NOLZCNT-NEXT: [[TOBOOL:%.*]] = icmp eq i32 [[SHR]], 0 |
| ; NOLZCNT-NEXT: br i1 [[TOBOOL]], label [[WHILE_END_LOOPEXIT:%.*]], label [[WHILE_BODY]] |
| ; NOLZCNT: while.end.loopexit: |
| ; NOLZCNT-NEXT: [[INDVARS_IV_NEXT_LCSSA:%.*]] = phi i64 [ [[INDVARS_IV_NEXT]], [[WHILE_BODY]] ] |
| ; NOLZCNT-NEXT: [[TMP1:%.*]] = trunc i64 [[INDVARS_IV_NEXT_LCSSA]] to i32 |
| ; NOLZCNT-NEXT: br label [[WHILE_END]] |
| ; NOLZCNT: while.end: |
| ; NOLZCNT-NEXT: [[I_0_LCSSA:%.*]] = phi i32 [ 0, [[ENTRY:%.*]] ], [ [[TMP1]], [[WHILE_END_LOOPEXIT]] ] |
| ; NOLZCNT-NEXT: ret i32 [[I_0_LCSSA]] |
| ; |
| entry: |
| %c = icmp sgt i32 %n, 0 |
| %negn = sub nsw i32 0, %n |
| %abs_n = select i1 %c, i32 %n, i32 %negn |
| %shr8 = lshr i32 %abs_n, 1 |
| %tobool9 = icmp eq i32 %shr8, 0 |
| br i1 %tobool9, label %while.end, label %while.body.preheader |
| |
| while.body.preheader: ; preds = %entry |
| br label %while.body |
| |
| while.body: ; preds = %while.body.preheader, %while.body |
| %indvars.iv = phi i64 [ %indvars.iv.next, %while.body ], [ 0, %while.body.preheader ] |
| %shr11 = phi i32 [ %shr, %while.body ], [ %shr8, %while.body.preheader ] |
| %0 = trunc i64 %indvars.iv to i32 |
| %shl = shl i32 1, %0 |
| %and = and i32 %shl, %abs_n |
| %tobool1 = icmp ne i32 %and, 0 |
| %conv = zext i1 %tobool1 to i8 |
| %arrayidx = getelementptr inbounds i8, i8* %a, i64 %indvars.iv |
| store i8 %conv, i8* %arrayidx, align 1 |
| %indvars.iv.next = add nuw i64 %indvars.iv, 1 |
| %shr = ashr i32 %shr11, 1 |
| %tobool = icmp eq i32 %shr, 0 |
| br i1 %tobool, label %while.end.loopexit, label %while.body |
| |
| while.end.loopexit: ; preds = %while.body |
| %1 = trunc i64 %indvars.iv.next to i32 |
| br label %while.end |
| |
| while.end: ; preds = %while.end.loopexit, %entry |
| %i.0.lcssa = phi i32 [ 0, %entry ], [ %1, %while.end.loopexit ] |
| ret i32 %i.0.lcssa |
| } |
| |
| ; Recognize CTLZ builtin pattern. |
| ; Here it will replace the loop - |
| ; assume builtin is always profitable. |
| ; |
| ; int ctlz_zero_check(int n) |
| ; { |
| ; n = n >= 0 ? n : -n; |
| ; int i = 0; |
| ; while(n) { |
| ; n >>= 1; |
| ; i++; |
| ; } |
| ; return i; |
| ; } |
| ; |
| define i32 @ctlz_zero_check(i32 %n) { |
| ; ALL-LABEL: @ctlz_zero_check( |
| ; ALL-NEXT: entry: |
| ; ALL-NEXT: [[C:%.*]] = icmp sgt i32 [[N:%.*]], 0 |
| ; ALL-NEXT: [[NEGN:%.*]] = sub nsw i32 0, [[N]] |
| ; ALL-NEXT: [[ABS_N:%.*]] = select i1 [[C]], i32 [[N]], i32 [[NEGN]] |
| ; ALL-NEXT: [[TOBOOL4:%.*]] = icmp eq i32 [[ABS_N]], 0 |
| ; ALL-NEXT: br i1 [[TOBOOL4]], label [[WHILE_END:%.*]], label [[WHILE_BODY_PREHEADER:%.*]] |
| ; ALL: while.body.preheader: |
| ; ALL-NEXT: [[TMP0:%.*]] = call i32 @llvm.ctlz.i32(i32 [[ABS_N]], i1 true) |
| ; ALL-NEXT: [[TMP1:%.*]] = sub i32 32, [[TMP0]] |
| ; ALL-NEXT: br label [[WHILE_BODY:%.*]] |
| ; ALL: while.body: |
| ; ALL-NEXT: [[TCPHI:%.*]] = phi i32 [ [[TMP1]], [[WHILE_BODY_PREHEADER]] ], [ [[TCDEC:%.*]], [[WHILE_BODY]] ] |
| ; ALL-NEXT: [[I_06:%.*]] = phi i32 [ [[INC:%.*]], [[WHILE_BODY]] ], [ 0, [[WHILE_BODY_PREHEADER]] ] |
| ; ALL-NEXT: [[N_ADDR_05:%.*]] = phi i32 [ [[SHR:%.*]], [[WHILE_BODY]] ], [ [[ABS_N]], [[WHILE_BODY_PREHEADER]] ] |
| ; ALL-NEXT: [[SHR]] = ashr i32 [[N_ADDR_05]], 1 |
| ; ALL-NEXT: [[INC]] = add nsw i32 [[I_06]], 1 |
| ; ALL-NEXT: [[TCDEC]] = sub nsw i32 [[TCPHI]], 1 |
| ; ALL-NEXT: [[TOBOOL:%.*]] = icmp eq i32 [[TCDEC]], 0 |
| ; ALL-NEXT: br i1 [[TOBOOL]], label [[WHILE_END_LOOPEXIT:%.*]], label [[WHILE_BODY]] |
| ; ALL: while.end.loopexit: |
| ; ALL-NEXT: [[INC_LCSSA:%.*]] = phi i32 [ [[TMP1]], [[WHILE_BODY]] ] |
| ; ALL-NEXT: br label [[WHILE_END]] |
| ; ALL: while.end: |
| ; ALL-NEXT: [[I_0_LCSSA:%.*]] = phi i32 [ 0, [[ENTRY:%.*]] ], [ [[INC_LCSSA]], [[WHILE_END_LOOPEXIT]] ] |
| ; ALL-NEXT: ret i32 [[I_0_LCSSA]] |
| ; |
| entry: |
| %c = icmp sgt i32 %n, 0 |
| %negn = sub nsw i32 0, %n |
| %abs_n = select i1 %c, i32 %n, i32 %negn |
| %tobool4 = icmp eq i32 %abs_n, 0 |
| br i1 %tobool4, label %while.end, label %while.body.preheader |
| |
| while.body.preheader: ; preds = %entry |
| br label %while.body |
| |
| while.body: ; preds = %while.body.preheader, %while.body |
| %i.06 = phi i32 [ %inc, %while.body ], [ 0, %while.body.preheader ] |
| %n.addr.05 = phi i32 [ %shr, %while.body ], [ %abs_n, %while.body.preheader ] |
| %shr = ashr i32 %n.addr.05, 1 |
| %inc = add nsw i32 %i.06, 1 |
| %tobool = icmp eq i32 %shr, 0 |
| br i1 %tobool, label %while.end.loopexit, label %while.body |
| |
| while.end.loopexit: ; preds = %while.body |
| br label %while.end |
| |
| while.end: ; preds = %while.end.loopexit, %entry |
| %i.0.lcssa = phi i32 [ 0, %entry ], [ %inc, %while.end.loopexit ] |
| ret i32 %i.0.lcssa |
| } |
| |
| ; Recognize CTLZ builtin pattern. |
| ; Here it will replace the loop - |
| ; assume builtin is always profitable. |
| ; |
| ; int ctlz_zero_check_lshr(int n) |
| ; { |
| ; int i = 0; |
| ; while(n) { |
| ; n >>= 1; |
| ; i++; |
| ; } |
| ; return i; |
| ; } |
| ; |
| define i32 @ctlz_zero_check_lshr(i32 %n) { |
| ; ALL-LABEL: @ctlz_zero_check_lshr( |
| ; ALL-NEXT: entry: |
| ; ALL-NEXT: [[TOBOOL4:%.*]] = icmp eq i32 [[N:%.*]], 0 |
| ; ALL-NEXT: br i1 [[TOBOOL4]], label [[WHILE_END:%.*]], label [[WHILE_BODY_PREHEADER:%.*]] |
| ; ALL: while.body.preheader: |
| ; ALL-NEXT: [[TMP0:%.*]] = call i32 @llvm.ctlz.i32(i32 [[N]], i1 true) |
| ; ALL-NEXT: [[TMP1:%.*]] = sub i32 32, [[TMP0]] |
| ; ALL-NEXT: br label [[WHILE_BODY:%.*]] |
| ; ALL: while.body: |
| ; ALL-NEXT: [[TCPHI:%.*]] = phi i32 [ [[TMP1]], [[WHILE_BODY_PREHEADER]] ], [ [[TCDEC:%.*]], [[WHILE_BODY]] ] |
| ; ALL-NEXT: [[I_06:%.*]] = phi i32 [ [[INC:%.*]], [[WHILE_BODY]] ], [ 0, [[WHILE_BODY_PREHEADER]] ] |
| ; ALL-NEXT: [[N_ADDR_05:%.*]] = phi i32 [ [[SHR:%.*]], [[WHILE_BODY]] ], [ [[N]], [[WHILE_BODY_PREHEADER]] ] |
| ; ALL-NEXT: [[SHR]] = lshr i32 [[N_ADDR_05]], 1 |
| ; ALL-NEXT: [[INC]] = add nsw i32 [[I_06]], 1 |
| ; ALL-NEXT: [[TCDEC]] = sub nsw i32 [[TCPHI]], 1 |
| ; ALL-NEXT: [[TOBOOL:%.*]] = icmp eq i32 [[TCDEC]], 0 |
| ; ALL-NEXT: br i1 [[TOBOOL]], label [[WHILE_END_LOOPEXIT:%.*]], label [[WHILE_BODY]] |
| ; ALL: while.end.loopexit: |
| ; ALL-NEXT: [[INC_LCSSA:%.*]] = phi i32 [ [[TMP1]], [[WHILE_BODY]] ] |
| ; ALL-NEXT: br label [[WHILE_END]] |
| ; ALL: while.end: |
| ; ALL-NEXT: [[I_0_LCSSA:%.*]] = phi i32 [ 0, [[ENTRY:%.*]] ], [ [[INC_LCSSA]], [[WHILE_END_LOOPEXIT]] ] |
| ; ALL-NEXT: ret i32 [[I_0_LCSSA]] |
| ; |
| entry: |
| %tobool4 = icmp eq i32 %n, 0 |
| br i1 %tobool4, label %while.end, label %while.body.preheader |
| |
| while.body.preheader: ; preds = %entry |
| br label %while.body |
| |
| while.body: ; preds = %while.body.preheader, %while.body |
| %i.06 = phi i32 [ %inc, %while.body ], [ 0, %while.body.preheader ] |
| %n.addr.05 = phi i32 [ %shr, %while.body ], [ %n, %while.body.preheader ] |
| %shr = lshr i32 %n.addr.05, 1 |
| %inc = add nsw i32 %i.06, 1 |
| %tobool = icmp eq i32 %shr, 0 |
| br i1 %tobool, label %while.end.loopexit, label %while.body |
| |
| while.end.loopexit: ; preds = %while.body |
| br label %while.end |
| |
| while.end: ; preds = %while.end.loopexit, %entry |
| %i.0.lcssa = phi i32 [ 0, %entry ], [ %inc, %while.end.loopexit ] |
| ret i32 %i.0.lcssa |
| } |
| |
| ; Recognize CTLZ builtin pattern. |
| ; Here it will replace the loop - |
| ; assume builtin is always profitable. |
| ; |
| ; int ctlz(int n) |
| ; { |
| ; n = n >= 0 ? n : -n; |
| ; int i = 0; |
| ; while(n >>= 1) { |
| ; i++; |
| ; } |
| ; return i; |
| ; } |
| ; |
| define i32 @ctlz(i32 %n) { |
| ; ALL-LABEL: @ctlz( |
| ; ALL-NEXT: entry: |
| ; ALL-NEXT: [[C:%.*]] = icmp sgt i32 [[N:%.*]], 0 |
| ; ALL-NEXT: [[NEGN:%.*]] = sub nsw i32 0, [[N]] |
| ; ALL-NEXT: [[ABS_N:%.*]] = select i1 [[C]], i32 [[N]], i32 [[NEGN]] |
| ; ALL-NEXT: [[TMP0:%.*]] = ashr i32 [[ABS_N]], 1 |
| ; ALL-NEXT: [[TMP1:%.*]] = call i32 @llvm.ctlz.i32(i32 [[TMP0]], i1 false) |
| ; ALL-NEXT: [[TMP2:%.*]] = sub i32 32, [[TMP1]] |
| ; ALL-NEXT: [[TMP3:%.*]] = add i32 [[TMP2]], 1 |
| ; ALL-NEXT: br label [[WHILE_COND:%.*]] |
| ; ALL: while.cond: |
| ; ALL-NEXT: [[TCPHI:%.*]] = phi i32 [ [[TMP3]], [[ENTRY:%.*]] ], [ [[TCDEC:%.*]], [[WHILE_COND]] ] |
| ; ALL-NEXT: [[N_ADDR_0:%.*]] = phi i32 [ [[ABS_N]], [[ENTRY]] ], [ [[SHR:%.*]], [[WHILE_COND]] ] |
| ; ALL-NEXT: [[I_0:%.*]] = phi i32 [ 0, [[ENTRY]] ], [ [[INC:%.*]], [[WHILE_COND]] ] |
| ; ALL-NEXT: [[SHR]] = ashr i32 [[N_ADDR_0]], 1 |
| ; ALL-NEXT: [[TCDEC]] = sub nsw i32 [[TCPHI]], 1 |
| ; ALL-NEXT: [[TOBOOL:%.*]] = icmp eq i32 [[TCDEC]], 0 |
| ; ALL-NEXT: [[INC]] = add nsw i32 [[I_0]], 1 |
| ; ALL-NEXT: br i1 [[TOBOOL]], label [[WHILE_END:%.*]], label [[WHILE_COND]] |
| ; ALL: while.end: |
| ; ALL-NEXT: [[I_0_LCSSA:%.*]] = phi i32 [ [[TMP2]], [[WHILE_COND]] ] |
| ; ALL-NEXT: ret i32 [[I_0_LCSSA]] |
| ; |
| entry: |
| %c = icmp sgt i32 %n, 0 |
| %negn = sub nsw i32 0, %n |
| %abs_n = select i1 %c, i32 %n, i32 %negn |
| br label %while.cond |
| |
| while.cond: ; preds = %while.cond, %entry |
| %n.addr.0 = phi i32 [ %abs_n, %entry ], [ %shr, %while.cond ] |
| %i.0 = phi i32 [ 0, %entry ], [ %inc, %while.cond ] |
| %shr = ashr i32 %n.addr.0, 1 |
| %tobool = icmp eq i32 %shr, 0 |
| %inc = add nsw i32 %i.0, 1 |
| br i1 %tobool, label %while.end, label %while.cond |
| |
| while.end: ; preds = %while.cond |
| ret i32 %i.0 |
| } |
| |
| ; Recognize CTLZ builtin pattern. |
| ; Here it will replace the loop - |
| ; assume builtin is always profitable. |
| ; |
| ; int ctlz_lshr(int n) |
| ; { |
| ; int i = 0; |
| ; while(n >>= 1) { |
| ; i++; |
| ; } |
| ; return i; |
| ; } |
| ; |
| define i32 @ctlz_lshr(i32 %n) { |
| ; ALL-LABEL: @ctlz_lshr( |
| ; ALL-NEXT: entry: |
| ; ALL-NEXT: [[TMP0:%.*]] = lshr i32 [[N:%.*]], 1 |
| ; ALL-NEXT: [[TMP1:%.*]] = call i32 @llvm.ctlz.i32(i32 [[TMP0]], i1 false) |
| ; ALL-NEXT: [[TMP2:%.*]] = sub i32 32, [[TMP1]] |
| ; ALL-NEXT: [[TMP3:%.*]] = add i32 [[TMP2]], 1 |
| ; ALL-NEXT: br label [[WHILE_COND:%.*]] |
| ; ALL: while.cond: |
| ; ALL-NEXT: [[TCPHI:%.*]] = phi i32 [ [[TMP3]], [[ENTRY:%.*]] ], [ [[TCDEC:%.*]], [[WHILE_COND]] ] |
| ; ALL-NEXT: [[N_ADDR_0:%.*]] = phi i32 [ [[N]], [[ENTRY]] ], [ [[SHR:%.*]], [[WHILE_COND]] ] |
| ; ALL-NEXT: [[I_0:%.*]] = phi i32 [ 0, [[ENTRY]] ], [ [[INC:%.*]], [[WHILE_COND]] ] |
| ; ALL-NEXT: [[SHR]] = lshr i32 [[N_ADDR_0]], 1 |
| ; ALL-NEXT: [[TCDEC]] = sub nsw i32 [[TCPHI]], 1 |
| ; ALL-NEXT: [[TOBOOL:%.*]] = icmp eq i32 [[TCDEC]], 0 |
| ; ALL-NEXT: [[INC]] = add nsw i32 [[I_0]], 1 |
| ; ALL-NEXT: br i1 [[TOBOOL]], label [[WHILE_END:%.*]], label [[WHILE_COND]] |
| ; ALL: while.end: |
| ; ALL-NEXT: [[I_0_LCSSA:%.*]] = phi i32 [ [[TMP2]], [[WHILE_COND]] ] |
| ; ALL-NEXT: ret i32 [[I_0_LCSSA]] |
| ; |
| entry: |
| br label %while.cond |
| |
| while.cond: ; preds = %while.cond, %entry |
| %n.addr.0 = phi i32 [ %n, %entry ], [ %shr, %while.cond ] |
| %i.0 = phi i32 [ 0, %entry ], [ %inc, %while.cond ] |
| %shr = lshr i32 %n.addr.0, 1 |
| %tobool = icmp eq i32 %shr, 0 |
| %inc = add nsw i32 %i.0, 1 |
| br i1 %tobool, label %while.end, label %while.cond |
| |
| while.end: ; preds = %while.cond |
| ret i32 %i.0 |
| } |
| |
| ; Recognize CTLZ builtin pattern. |
| ; Here it will replace the loop - |
| ; assume builtin is always profitable. |
| ; |
| ; int ctlz_add(int n, int i0) |
| ; { |
| ; n = n >= 0 ? n : -n; |
| ; int i = i0; |
| ; while(n >>= 1) { |
| ; i++; |
| ; } |
| ; return i; |
| ; } |
| ; |
| define i32 @ctlz_add(i32 %n, i32 %i0) { |
| ; ALL-LABEL: @ctlz_add( |
| ; ALL-NEXT: entry: |
| ; ALL-NEXT: [[C:%.*]] = icmp sgt i32 [[N:%.*]], 0 |
| ; ALL-NEXT: [[NEGN:%.*]] = sub nsw i32 0, [[N]] |
| ; ALL-NEXT: [[ABS_N:%.*]] = select i1 [[C]], i32 [[N]], i32 [[NEGN]] |
| ; ALL-NEXT: [[TMP0:%.*]] = ashr i32 [[ABS_N]], 1 |
| ; ALL-NEXT: [[TMP1:%.*]] = call i32 @llvm.ctlz.i32(i32 [[TMP0]], i1 false) |
| ; ALL-NEXT: [[TMP2:%.*]] = sub i32 32, [[TMP1]] |
| ; ALL-NEXT: [[TMP3:%.*]] = add i32 [[TMP2]], 1 |
| ; ALL-NEXT: [[TMP4:%.*]] = add i32 [[TMP2]], [[I0:%.*]] |
| ; ALL-NEXT: br label [[WHILE_COND:%.*]] |
| ; ALL: while.cond: |
| ; ALL-NEXT: [[TCPHI:%.*]] = phi i32 [ [[TMP3]], [[ENTRY:%.*]] ], [ [[TCDEC:%.*]], [[WHILE_COND]] ] |
| ; ALL-NEXT: [[N_ADDR_0:%.*]] = phi i32 [ [[ABS_N]], [[ENTRY]] ], [ [[SHR:%.*]], [[WHILE_COND]] ] |
| ; ALL-NEXT: [[I_0:%.*]] = phi i32 [ [[I0]], [[ENTRY]] ], [ [[INC:%.*]], [[WHILE_COND]] ] |
| ; ALL-NEXT: [[SHR]] = ashr i32 [[N_ADDR_0]], 1 |
| ; ALL-NEXT: [[TCDEC]] = sub nsw i32 [[TCPHI]], 1 |
| ; ALL-NEXT: [[TOBOOL:%.*]] = icmp eq i32 [[TCDEC]], 0 |
| ; ALL-NEXT: [[INC]] = add nsw i32 [[I_0]], 1 |
| ; ALL-NEXT: br i1 [[TOBOOL]], label [[WHILE_END:%.*]], label [[WHILE_COND]] |
| ; ALL: while.end: |
| ; ALL-NEXT: [[I_0_LCSSA:%.*]] = phi i32 [ [[TMP4]], [[WHILE_COND]] ] |
| ; ALL-NEXT: ret i32 [[I_0_LCSSA]] |
| ; |
| entry: |
| %c = icmp sgt i32 %n, 0 |
| %negn = sub nsw i32 0, %n |
| %abs_n = select i1 %c, i32 %n, i32 %negn |
| br label %while.cond |
| |
| while.cond: ; preds = %while.cond, %entry |
| %n.addr.0 = phi i32 [ %abs_n, %entry ], [ %shr, %while.cond ] |
| %i.0 = phi i32 [ %i0, %entry ], [ %inc, %while.cond ] |
| %shr = ashr i32 %n.addr.0, 1 |
| %tobool = icmp eq i32 %shr, 0 |
| %inc = add nsw i32 %i.0, 1 |
| br i1 %tobool, label %while.end, label %while.cond |
| |
| while.end: ; preds = %while.cond |
| ret i32 %i.0 |
| } |
| |
| ; Recognize CTLZ builtin pattern. |
| ; Here it will replace the loop - |
| ; assume builtin is always profitable. |
| ; |
| ; int ctlz_add_lshr(int n, int i0) |
| ; { |
| ; int i = i0; |
| ; while(n >>= 1) { |
| ; i++; |
| ; } |
| ; return i; |
| ; } |
| ; |
| define i32 @ctlz_add_lshr(i32 %n, i32 %i0) { |
| ; ALL-LABEL: @ctlz_add_lshr( |
| ; ALL-NEXT: entry: |
| ; ALL-NEXT: [[TMP0:%.*]] = lshr i32 [[N:%.*]], 1 |
| ; ALL-NEXT: [[TMP1:%.*]] = call i32 @llvm.ctlz.i32(i32 [[TMP0]], i1 false) |
| ; ALL-NEXT: [[TMP2:%.*]] = sub i32 32, [[TMP1]] |
| ; ALL-NEXT: [[TMP3:%.*]] = add i32 [[TMP2]], 1 |
| ; ALL-NEXT: [[TMP4:%.*]] = add i32 [[TMP2]], [[I0:%.*]] |
| ; ALL-NEXT: br label [[WHILE_COND:%.*]] |
| ; ALL: while.cond: |
| ; ALL-NEXT: [[TCPHI:%.*]] = phi i32 [ [[TMP3]], [[ENTRY:%.*]] ], [ [[TCDEC:%.*]], [[WHILE_COND]] ] |
| ; ALL-NEXT: [[N_ADDR_0:%.*]] = phi i32 [ [[N]], [[ENTRY]] ], [ [[SHR:%.*]], [[WHILE_COND]] ] |
| ; ALL-NEXT: [[I_0:%.*]] = phi i32 [ [[I0]], [[ENTRY]] ], [ [[INC:%.*]], [[WHILE_COND]] ] |
| ; ALL-NEXT: [[SHR]] = lshr i32 [[N_ADDR_0]], 1 |
| ; ALL-NEXT: [[TCDEC]] = sub nsw i32 [[TCPHI]], 1 |
| ; ALL-NEXT: [[TOBOOL:%.*]] = icmp eq i32 [[TCDEC]], 0 |
| ; ALL-NEXT: [[INC]] = add nsw i32 [[I_0]], 1 |
| ; ALL-NEXT: br i1 [[TOBOOL]], label [[WHILE_END:%.*]], label [[WHILE_COND]] |
| ; ALL: while.end: |
| ; ALL-NEXT: [[I_0_LCSSA:%.*]] = phi i32 [ [[TMP4]], [[WHILE_COND]] ] |
| ; ALL-NEXT: ret i32 [[I_0_LCSSA]] |
| ; |
| entry: |
| br label %while.cond |
| |
| while.cond: ; preds = %while.cond, %entry |
| %n.addr.0 = phi i32 [ %n, %entry ], [ %shr, %while.cond ] |
| %i.0 = phi i32 [ %i0, %entry ], [ %inc, %while.cond ] |
| %shr = lshr i32 %n.addr.0, 1 |
| %tobool = icmp eq i32 %shr, 0 |
| %inc = add nsw i32 %i.0, 1 |
| br i1 %tobool, label %while.end, label %while.cond |
| |
| while.end: ; preds = %while.cond |
| ret i32 %i.0 |
| } |
| |
| ; Recognize CTLZ builtin pattern. |
| ; Here it will replace the loop - |
| ; assume builtin is always profitable. |
| ; |
| ; int ctlz_sext(short in) |
| ; { |
| ; int n = in; |
| ; if (in < 0) |
| ; n = -n; |
| ; int i = 0; |
| ; while(n >>= 1) { |
| ; i++; |
| ; } |
| ; return i; |
| ; } |
| ; |
| define i32 @ctlz_sext(i16 %in) { |
| ; ALL-LABEL: @ctlz_sext( |
| ; ALL-NEXT: entry: |
| ; ALL-NEXT: [[N:%.*]] = sext i16 [[IN:%.*]] to i32 |
| ; ALL-NEXT: [[C:%.*]] = icmp sgt i16 [[IN]], 0 |
| ; ALL-NEXT: [[NEGN:%.*]] = sub nsw i32 0, [[N]] |
| ; ALL-NEXT: [[ABS_N:%.*]] = select i1 [[C]], i32 [[N]], i32 [[NEGN]] |
| ; ALL-NEXT: [[TMP0:%.*]] = ashr i32 [[ABS_N]], 1 |
| ; ALL-NEXT: [[TMP1:%.*]] = call i32 @llvm.ctlz.i32(i32 [[TMP0]], i1 false) |
| ; ALL-NEXT: [[TMP2:%.*]] = sub i32 32, [[TMP1]] |
| ; ALL-NEXT: [[TMP3:%.*]] = add i32 [[TMP2]], 1 |
| ; ALL-NEXT: br label [[WHILE_COND:%.*]] |
| ; ALL: while.cond: |
| ; ALL-NEXT: [[TCPHI:%.*]] = phi i32 [ [[TMP3]], [[ENTRY:%.*]] ], [ [[TCDEC:%.*]], [[WHILE_COND]] ] |
| ; ALL-NEXT: [[N_ADDR_0:%.*]] = phi i32 [ [[ABS_N]], [[ENTRY]] ], [ [[SHR:%.*]], [[WHILE_COND]] ] |
| ; ALL-NEXT: [[I_0:%.*]] = phi i32 [ 0, [[ENTRY]] ], [ [[INC:%.*]], [[WHILE_COND]] ] |
| ; ALL-NEXT: [[SHR]] = ashr i32 [[N_ADDR_0]], 1 |
| ; ALL-NEXT: [[TCDEC]] = sub nsw i32 [[TCPHI]], 1 |
| ; ALL-NEXT: [[TOBOOL:%.*]] = icmp eq i32 [[TCDEC]], 0 |
| ; ALL-NEXT: [[INC]] = add nsw i32 [[I_0]], 1 |
| ; ALL-NEXT: br i1 [[TOBOOL]], label [[WHILE_END:%.*]], label [[WHILE_COND]] |
| ; ALL: while.end: |
| ; ALL-NEXT: [[I_0_LCSSA:%.*]] = phi i32 [ [[TMP2]], [[WHILE_COND]] ] |
| ; ALL-NEXT: ret i32 [[I_0_LCSSA]] |
| ; |
| entry: |
| %n = sext i16 %in to i32 |
| %c = icmp sgt i16 %in, 0 |
| %negn = sub nsw i32 0, %n |
| %abs_n = select i1 %c, i32 %n, i32 %negn |
| br label %while.cond |
| |
| while.cond: ; preds = %while.cond, %entry |
| %n.addr.0 = phi i32 [ %abs_n, %entry ], [ %shr, %while.cond ] |
| %i.0 = phi i32 [ 0, %entry ], [ %inc, %while.cond ] |
| %shr = ashr i32 %n.addr.0, 1 |
| %tobool = icmp eq i32 %shr, 0 |
| %inc = add nsw i32 %i.0, 1 |
| br i1 %tobool, label %while.end, label %while.cond |
| |
| while.end: ; preds = %while.cond |
| ret i32 %i.0 |
| } |
| |
| ; Recognize CTLZ builtin pattern. |
| ; Here it will replace the loop - |
| ; assume builtin is always profitable. |
| ; |
| ; int ctlz_sext_lshr(short in) |
| ; { |
| ; int i = 0; |
| ; while(in >>= 1) { |
| ; i++; |
| ; } |
| ; return i; |
| ; } |
| ; |
| define i32 @ctlz_sext_lshr(i16 %in) { |
| ; ALL-LABEL: @ctlz_sext_lshr( |
| ; ALL-NEXT: entry: |
| ; ALL-NEXT: [[N:%.*]] = sext i16 [[IN:%.*]] to i32 |
| ; ALL-NEXT: [[TMP0:%.*]] = lshr i32 [[N]], 1 |
| ; ALL-NEXT: [[TMP1:%.*]] = call i32 @llvm.ctlz.i32(i32 [[TMP0]], i1 false) |
| ; ALL-NEXT: [[TMP2:%.*]] = sub i32 32, [[TMP1]] |
| ; ALL-NEXT: [[TMP3:%.*]] = add i32 [[TMP2]], 1 |
| ; ALL-NEXT: br label [[WHILE_COND:%.*]] |
| ; ALL: while.cond: |
| ; ALL-NEXT: [[TCPHI:%.*]] = phi i32 [ [[TMP3]], [[ENTRY:%.*]] ], [ [[TCDEC:%.*]], [[WHILE_COND]] ] |
| ; ALL-NEXT: [[N_ADDR_0:%.*]] = phi i32 [ [[N]], [[ENTRY]] ], [ [[SHR:%.*]], [[WHILE_COND]] ] |
| ; ALL-NEXT: [[I_0:%.*]] = phi i32 [ 0, [[ENTRY]] ], [ [[INC:%.*]], [[WHILE_COND]] ] |
| ; ALL-NEXT: [[SHR]] = lshr i32 [[N_ADDR_0]], 1 |
| ; ALL-NEXT: [[TCDEC]] = sub nsw i32 [[TCPHI]], 1 |
| ; ALL-NEXT: [[TOBOOL:%.*]] = icmp eq i32 [[TCDEC]], 0 |
| ; ALL-NEXT: [[INC]] = add nsw i32 [[I_0]], 1 |
| ; ALL-NEXT: br i1 [[TOBOOL]], label [[WHILE_END:%.*]], label [[WHILE_COND]] |
| ; ALL: while.end: |
| ; ALL-NEXT: [[I_0_LCSSA:%.*]] = phi i32 [ [[TMP2]], [[WHILE_COND]] ] |
| ; ALL-NEXT: ret i32 [[I_0_LCSSA]] |
| ; |
| entry: |
| %n = sext i16 %in to i32 |
| br label %while.cond |
| |
| while.cond: ; preds = %while.cond, %entry |
| %n.addr.0 = phi i32 [ %n, %entry ], [ %shr, %while.cond ] |
| %i.0 = phi i32 [ 0, %entry ], [ %inc, %while.cond ] |
| %shr = lshr i32 %n.addr.0, 1 |
| %tobool = icmp eq i32 %shr, 0 |
| %inc = add nsw i32 %i.0, 1 |
| br i1 %tobool, label %while.end, label %while.cond |
| |
| while.end: ; preds = %while.cond |
| ret i32 %i.0 |
| } |
| |
| ; This loop contains a volatile store. If x is initially negative, |
| ; the code will be an infinite loop because the ashr will eventually produce |
| ; all ones and continue doing so. This prevents the loop from terminating. If |
| ; we convert this to a countable loop using ctlz that loop will only run 32 |
| ; times. This is different than the infinite number of times of the original. |
| define i32 @foo(i32 %x) { |
| ; ALL-LABEL: @foo( |
| ; ALL-NEXT: entry: |
| ; ALL-NEXT: [[V:%.*]] = alloca i8, align 1 |
| ; ALL-NEXT: [[TOBOOL4:%.*]] = icmp eq i32 [[X:%.*]], 0 |
| ; ALL-NEXT: br i1 [[TOBOOL4]], label [[WHILE_END:%.*]], label [[WHILE_BODY_LR_PH:%.*]] |
| ; ALL: while.body.lr.ph: |
| ; ALL-NEXT: br label [[WHILE_BODY:%.*]] |
| ; ALL: while.body: |
| ; ALL-NEXT: [[CNT_06:%.*]] = phi i32 [ 0, [[WHILE_BODY_LR_PH]] ], [ [[INC:%.*]], [[WHILE_BODY]] ] |
| ; ALL-NEXT: [[X_ADDR_05:%.*]] = phi i32 [ [[X]], [[WHILE_BODY_LR_PH]] ], [ [[SHR:%.*]], [[WHILE_BODY]] ] |
| ; ALL-NEXT: [[SHR]] = ashr i32 [[X_ADDR_05]], 1 |
| ; ALL-NEXT: [[INC]] = add i32 [[CNT_06]], 1 |
| ; ALL-NEXT: store volatile i8 42, i8* [[V]], align 1 |
| ; ALL-NEXT: [[TOBOOL:%.*]] = icmp eq i32 [[SHR]], 0 |
| ; ALL-NEXT: br i1 [[TOBOOL]], label [[WHILE_COND_WHILE_END_CRIT_EDGE:%.*]], label [[WHILE_BODY]] |
| ; ALL: while.cond.while.end_crit_edge: |
| ; ALL-NEXT: [[SPLIT:%.*]] = phi i32 [ [[INC]], [[WHILE_BODY]] ] |
| ; ALL-NEXT: br label [[WHILE_END]] |
| ; ALL: while.end: |
| ; ALL-NEXT: [[CNT_0_LCSSA:%.*]] = phi i32 [ [[SPLIT]], [[WHILE_COND_WHILE_END_CRIT_EDGE]] ], [ 0, [[ENTRY:%.*]] ] |
| ; ALL-NEXT: ret i32 [[CNT_0_LCSSA]] |
| ; |
| entry: |
| %v = alloca i8, align 1 |
| %tobool4 = icmp eq i32 %x, 0 |
| br i1 %tobool4, label %while.end, label %while.body.lr.ph |
| |
| while.body.lr.ph: ; preds = %entry |
| br label %while.body |
| |
| while.body: ; preds = %while.body.lr.ph, %while.body |
| %cnt.06 = phi i32 [ 0, %while.body.lr.ph ], [ %inc, %while.body ] |
| %x.addr.05 = phi i32 [ %x, %while.body.lr.ph ], [ %shr, %while.body ] |
| %shr = ashr i32 %x.addr.05, 1 |
| %inc = add i32 %cnt.06, 1 |
| store volatile i8 42, i8* %v, align 1 |
| %tobool = icmp eq i32 %shr, 0 |
| br i1 %tobool, label %while.cond.while.end_crit_edge, label %while.body |
| |
| while.cond.while.end_crit_edge: ; preds = %while.body |
| %split = phi i32 [ %inc, %while.body ] |
| br label %while.end |
| |
| while.end: ; preds = %while.cond.while.end_crit_edge, %entry |
| %cnt.0.lcssa = phi i32 [ %split, %while.cond.while.end_crit_edge ], [ 0, %entry ] |
| ret i32 %cnt.0.lcssa |
| } |
| |
| ; We can't easily transform this loop. It returns 1 for an input of both |
| ; 0 and 1. |
| ; |
| ; int ctlz_bad(unsigned n) |
| ; { |
| ; int i = 0; |
| ; do { |
| ; i++; |
| ; n >>= 1; |
| ; } while(n != 0) { |
| ; return i; |
| ; } |
| ; |
| define i32 @ctlz_bad(i32 %n) { |
| ; ALL-LABEL: @ctlz_bad( |
| ; ALL-NEXT: entry: |
| ; ALL-NEXT: br label [[WHILE_COND:%.*]] |
| ; ALL: while.cond: |
| ; ALL-NEXT: [[N_ADDR_0:%.*]] = phi i32 [ [[N:%.*]], [[ENTRY:%.*]] ], [ [[SHR:%.*]], [[WHILE_COND]] ] |
| ; ALL-NEXT: [[I_0:%.*]] = phi i32 [ 0, [[ENTRY]] ], [ [[INC:%.*]], [[WHILE_COND]] ] |
| ; ALL-NEXT: [[SHR]] = lshr i32 [[N_ADDR_0]], 1 |
| ; ALL-NEXT: [[TOBOOL:%.*]] = icmp eq i32 [[SHR]], 0 |
| ; ALL-NEXT: [[INC]] = add nsw i32 [[I_0]], 1 |
| ; ALL-NEXT: br i1 [[TOBOOL]], label [[WHILE_END:%.*]], label [[WHILE_COND]] |
| ; ALL: while.end: |
| ; ALL-NEXT: [[INC_LCSSA:%.*]] = phi i32 [ [[INC]], [[WHILE_COND]] ] |
| ; ALL-NEXT: ret i32 [[INC_LCSSA]] |
| ; |
| entry: |
| br label %while.cond |
| |
| while.cond: ; preds = %while.cond, %entry |
| %n.addr.0 = phi i32 [ %n, %entry ], [ %shr, %while.cond ] |
| %i.0 = phi i32 [ 0, %entry ], [ %inc, %while.cond ] |
| %shr = lshr i32 %n.addr.0, 1 |
| %tobool = icmp eq i32 %shr, 0 |
| %inc = add nsw i32 %i.0, 1 |
| br i1 %tobool, label %while.end, label %while.cond |
| |
| while.end: ; preds = %while.cond |
| ret i32 %inc |
| } |
| |
| ; Recognize CTLZ builtin pattern. |
| ; Here it will replace the loop - |
| ; assume builtin is always profitable. |
| ; |
| ; int ctlz_decrement(int n) |
| ; { |
| ; int i = 32; |
| ; while(n) { |
| ; n >>= 1; |
| ; i--; |
| ; } |
| ; return i; |
| ; } |
| ; |
| define i32 @ctlz_decrement(i32 %n) { |
| ; ALL-LABEL: @ctlz_decrement( |
| ; ALL-NEXT: entry: |
| ; ALL-NEXT: [[TOBOOL4:%.*]] = icmp eq i32 [[N:%.*]], 0 |
| ; ALL-NEXT: br i1 [[TOBOOL4]], label [[WHILE_END:%.*]], label [[WHILE_BODY_PREHEADER:%.*]] |
| ; ALL: while.body.preheader: |
| ; ALL-NEXT: [[TMP0:%.*]] = call i32 @llvm.ctlz.i32(i32 [[N]], i1 true) |
| ; ALL-NEXT: [[TMP1:%.*]] = sub i32 32, [[TMP0]] |
| ; ALL-NEXT: [[TMP2:%.*]] = sub i32 32, [[TMP1]] |
| ; ALL-NEXT: br label [[WHILE_BODY:%.*]] |
| ; ALL: while.body: |
| ; ALL-NEXT: [[TCPHI:%.*]] = phi i32 [ [[TMP1]], [[WHILE_BODY_PREHEADER]] ], [ [[TCDEC:%.*]], [[WHILE_BODY]] ] |
| ; ALL-NEXT: [[I_06:%.*]] = phi i32 [ [[INC:%.*]], [[WHILE_BODY]] ], [ 32, [[WHILE_BODY_PREHEADER]] ] |
| ; ALL-NEXT: [[N_ADDR_05:%.*]] = phi i32 [ [[SHR:%.*]], [[WHILE_BODY]] ], [ [[N]], [[WHILE_BODY_PREHEADER]] ] |
| ; ALL-NEXT: [[SHR]] = lshr i32 [[N_ADDR_05]], 1 |
| ; ALL-NEXT: [[INC]] = add nsw i32 [[I_06]], -1 |
| ; ALL-NEXT: [[TCDEC]] = sub nsw i32 [[TCPHI]], 1 |
| ; ALL-NEXT: [[TOBOOL:%.*]] = icmp eq i32 [[TCDEC]], 0 |
| ; ALL-NEXT: br i1 [[TOBOOL]], label [[WHILE_END_LOOPEXIT:%.*]], label [[WHILE_BODY]] |
| ; ALL: while.end.loopexit: |
| ; ALL-NEXT: [[INC_LCSSA:%.*]] = phi i32 [ [[TMP2]], [[WHILE_BODY]] ] |
| ; ALL-NEXT: br label [[WHILE_END]] |
| ; ALL: while.end: |
| ; ALL-NEXT: [[I_0_LCSSA:%.*]] = phi i32 [ 32, [[ENTRY:%.*]] ], [ [[INC_LCSSA]], [[WHILE_END_LOOPEXIT]] ] |
| ; ALL-NEXT: ret i32 [[I_0_LCSSA]] |
| ; |
| entry: |
| %tobool4 = icmp eq i32 %n, 0 |
| br i1 %tobool4, label %while.end, label %while.body.preheader |
| |
| while.body.preheader: ; preds = %entry |
| br label %while.body |
| |
| while.body: ; preds = %while.body.preheader, %while.body |
| %i.06 = phi i32 [ %inc, %while.body ], [ 32, %while.body.preheader ] |
| %n.addr.05 = phi i32 [ %shr, %while.body ], [ %n, %while.body.preheader ] |
| %shr = lshr i32 %n.addr.05, 1 |
| %inc = add nsw i32 %i.06, -1 |
| %tobool = icmp eq i32 %shr, 0 |
| br i1 %tobool, label %while.end.loopexit, label %while.body |
| |
| while.end.loopexit: ; preds = %while.body |
| br label %while.end |
| |
| while.end: ; preds = %while.end.loopexit, %entry |
| %i.0.lcssa = phi i32 [ 32, %entry ], [ %inc, %while.end.loopexit ] |
| ret i32 %i.0.lcssa |
| } |
| |
| ; Recognize CTLZ builtin pattern. |
| ; Here it will replace the loop - |
| ; assume builtin is always profitable. |
| ; |
| ; int ctlz_lshr_decrement(int n) |
| ; { |
| ; int i = 31; |
| ; while(n >>= 1) { |
| ; i--; |
| ; } |
| ; return i; |
| ; } |
| ; |
| define i32 @ctlz_lshr_decrement(i32 %n) { |
| ; ALL-LABEL: @ctlz_lshr_decrement( |
| ; ALL-NEXT: entry: |
| ; ALL-NEXT: [[TMP0:%.*]] = lshr i32 [[N:%.*]], 1 |
| ; ALL-NEXT: [[TMP1:%.*]] = call i32 @llvm.ctlz.i32(i32 [[TMP0]], i1 false) |
| ; ALL-NEXT: [[TMP2:%.*]] = sub i32 32, [[TMP1]] |
| ; ALL-NEXT: [[TMP3:%.*]] = add i32 [[TMP2]], 1 |
| ; ALL-NEXT: [[TMP4:%.*]] = sub i32 31, [[TMP2]] |
| ; ALL-NEXT: br label [[WHILE_COND:%.*]] |
| ; ALL: while.cond: |
| ; ALL-NEXT: [[TCPHI:%.*]] = phi i32 [ [[TMP3]], [[ENTRY:%.*]] ], [ [[TCDEC:%.*]], [[WHILE_COND]] ] |
| ; ALL-NEXT: [[N_ADDR_0:%.*]] = phi i32 [ [[N]], [[ENTRY]] ], [ [[SHR:%.*]], [[WHILE_COND]] ] |
| ; ALL-NEXT: [[I_0:%.*]] = phi i32 [ 31, [[ENTRY]] ], [ [[INC:%.*]], [[WHILE_COND]] ] |
| ; ALL-NEXT: [[SHR]] = lshr i32 [[N_ADDR_0]], 1 |
| ; ALL-NEXT: [[TCDEC]] = sub nsw i32 [[TCPHI]], 1 |
| ; ALL-NEXT: [[TOBOOL:%.*]] = icmp eq i32 [[TCDEC]], 0 |
| ; ALL-NEXT: [[INC]] = add nsw i32 [[I_0]], -1 |
| ; ALL-NEXT: br i1 [[TOBOOL]], label [[WHILE_END:%.*]], label [[WHILE_COND]] |
| ; ALL: while.end: |
| ; ALL-NEXT: [[I_0_LCSSA:%.*]] = phi i32 [ [[TMP4]], [[WHILE_COND]] ] |
| ; ALL-NEXT: ret i32 [[I_0_LCSSA]] |
| ; |
| entry: |
| br label %while.cond |
| |
| while.cond: ; preds = %while.cond, %entry |
| %n.addr.0 = phi i32 [ %n, %entry ], [ %shr, %while.cond ] |
| %i.0 = phi i32 [ 31, %entry ], [ %inc, %while.cond ] |
| %shr = lshr i32 %n.addr.0, 1 |
| %tobool = icmp eq i32 %shr, 0 |
| %inc = add nsw i32 %i.0, -1 |
| br i1 %tobool, label %while.end, label %while.cond |
| |
| while.end: ; preds = %while.cond |
| ret i32 %i.0 |
| } |