| ; When optimising for minimum size, we don't want to expand a div to a mul |
| ; and a shift sequence. As a result, the urem instruction e.g. will not be |
| ; expanded to a sequence of umull, lsrs, muls and sub instructions, but |
| ; just a call to __aeabi_uidivmod. |
| ; |
| ; When the processor features hardware division, UDIV + UREM can be turned |
| ; into UDIV + MLS. This prevents the library function __aeabi_uidivmod to be |
| ; pulled into the binary. The test uses ARMv7-M. |
| ; |
| ; RUN: llc -mtriple=armv7a-eabi -mattr=-neon -verify-machineinstrs %s -o - | FileCheck %s |
| ; RUN: llc -mtriple=thumbv7m-eabi -verify-machineinstrs %s -o - | FileCheck %s -check-prefix=V7M |
| |
| target datalayout = "e-m:e-p:32:32-i64:64-v128:64:128-a:0:32-n32-S64" |
| target triple = "thumbv7m-arm-none-eabi" |
| |
| define i32 @foo1() local_unnamed_addr #0 { |
| entry: |
| ; CHECK-LABEL: foo1: |
| ; CHECK:__aeabi_idiv |
| ; CHECK-NOT: smmul |
| %call = tail call i32 @GetValue() |
| %div = sdiv i32 %call, 1000000 |
| ret i32 %div |
| } |
| |
| define i32 @foo2() local_unnamed_addr #0 { |
| entry: |
| ; CHECK-LABEL: foo2: |
| ; CHECK: __aeabi_uidiv |
| ; CHECK-NOT: umull |
| %call = tail call i32 @GetValue() |
| %div = udiv i32 %call, 1000000 |
| ret i32 %div |
| } |
| |
| ; Test for unsigned remainder |
| define i32 @foo3() local_unnamed_addr #0 { |
| entry: |
| ; CHECK-LABEL: foo3: |
| ; CHECK: __aeabi_uidivmod |
| ; CHECK-NOT: umull |
| ; V7M-LABEL: foo3: |
| ; V7M: udiv [[R2:r[0-9]+]], [[R0:r[0-9]+]], [[R1:r[0-9]+]] |
| ; V7M: mls {{r[0-9]+}}, [[R2]], [[R1]], [[R0]] |
| ; V7M-NOT: __aeabi_uidivmod |
| %call = tail call i32 @GetValue() |
| %rem = urem i32 %call, 1000000 |
| %cmp = icmp eq i32 %rem, 0 |
| %conv = zext i1 %cmp to i32 |
| ret i32 %conv |
| } |
| |
| ; Test for signed remainder |
| define i32 @foo4() local_unnamed_addr #0 { |
| entry: |
| ; CHECK-LABEL: foo4: |
| ; CHECK:__aeabi_idivmod |
| ; V7M-LABEL: foo4: |
| ; V7M: sdiv [[R2:r[0-9]+]], [[R0:r[0-9]+]], [[R1:r[0-9]+]] |
| ; V7M: mls {{r[0-9]+}}, [[R2]], [[R1]], [[R0]] |
| ; V7M-NOT: __aeabi_idivmod |
| %call = tail call i32 @GetValue() |
| %rem = srem i32 %call, 1000000 |
| ret i32 %rem |
| } |
| |
| ; Check that doing a sdiv+srem has the same effect as only the srem, |
| ; as the division needs to be computed anyway in order to calculate |
| ; the remainder (i.e. make sure we don't end up with two divisions). |
| define i32 @foo5() local_unnamed_addr #0 { |
| entry: |
| ; CHECK-LABEL: foo5: |
| ; CHECK:__aeabi_idivmod |
| ; V7M-LABEL: foo5: |
| ; V7M: sdiv [[R2:r[0-9]+]], [[R0:r[0-9]+]], [[R1:r[0-9]+]] |
| ; V7M-NOT: sdiv |
| ; V7M: mls {{r[0-9]+}}, [[R2]], [[R1]], [[R0]] |
| ; V7M-NOT: __aeabi_idivmod |
| %call = tail call i32 @GetValue() |
| %div = sdiv i32 %call, 1000000 |
| %rem = srem i32 %call, 1000000 |
| %add = add i32 %div, %rem |
| ret i32 %add |
| } |
| |
| ; An early version of this patch caused isel to hang. The reason |
| ; was that it shouldn't do the rewrite for i64 because that's not |
| ; supported by hardware. Isel was stuck in a loop with type |
| ; legalization and this optimisation. |
| ; Function Attrs: norecurse nounwind |
| define i64 @isel_dont_hang(i32 %bar) local_unnamed_addr #4 { |
| entry: |
| ; CHECK-LABEL: isel_dont_hang: |
| ; CHECK: __aeabi_uldivmod |
| %temp.0 = sext i32 %bar to i64 |
| %mul83 = shl i64 %temp.0, 1 |
| %add84 = add i64 %temp.0, 2 |
| %div85 = udiv i64 %mul83, %add84 |
| ret i64 %div85 |
| } |
| |
| ; i16 types are promoted to i32, and we expect a normal udiv here: |
| define i16 @isel_dont_hang_2(i16 %bar) local_unnamed_addr #4 { |
| entry: |
| ; CHECK-LABEL: isel_dont_hang_2: |
| ; CHECK: udiv |
| ; CHECK-NOT: __aeabi_ |
| %mul83 = shl i16 %bar, 1 |
| %add84 = add i16 %bar, 2 |
| %div85 = udiv i16 %mul83, %add84 |
| ret i16 %div85 |
| } |
| declare i32 @GetValue(...) local_unnamed_addr |
| |
| attributes #0 = { minsize nounwind optsize } |
| attributes #4 = { norecurse nounwind "correctly-rounded-divide-sqrt-fp-math"="false" "disable-tail-calls"="false" "less-precise-fpmad"="false" "frame-pointer"="all" "no-jump-tables"="false" "stack-protector-buffer-size"="8" "target-cpu"="cortex-a15" "target-features"="+dsp,+hwdiv,+hwdiv-arm,+neon,+vfp4" "use-soft-float"="false" } |
| |