[llvm] 57de4e0 - [TypePromotion] Don't insert Truncate for a no-op ZExt
Andre Vieira via llvm-commits
llvm-commits at lists.llvm.org
Thu Aug 11 01:50:23 PDT 2022
Author: Andre Vieira
Date: 2022-08-11T09:50:10+01:00
New Revision: 57de4e059ddcf97aa7cf22b1a94a018c66579f64
URL: https://github.com/llvm/llvm-project/commit/57de4e059ddcf97aa7cf22b1a94a018c66579f64
DIFF: https://github.com/llvm/llvm-project/commit/57de4e059ddcf97aa7cf22b1a94a018c66579f64.diff
LOG: [TypePromotion] Don't insert Truncate for a no-op ZExt
Differential Revision: https://reviews.llvm.org/D131487
Added:
Modified:
llvm/lib/CodeGen/TypePromotion.cpp
llvm/test/Transforms/TypePromotion/AArch64/phi-zext-gep.ll
llvm/test/Transforms/TypePromotion/ARM/calls.ll
llvm/test/Transforms/TypePromotion/ARM/casts.ll
Removed:
################################################################################
diff --git a/llvm/lib/CodeGen/TypePromotion.cpp b/llvm/lib/CodeGen/TypePromotion.cpp
index 8dc8d381ad166..0690fadab7eb7 100644
--- a/llvm/lib/CodeGen/TypePromotion.cpp
+++ b/llvm/lib/CodeGen/TypePromotion.cpp
@@ -551,8 +551,13 @@ void IRPromoter::TruncateSinks() {
}
// Don't insert a trunc for a zext which can still legally promote.
+ // Nor insert a trunc when the input value to that trunc has the same width
+ // as the zext we are inserting it for. When this happens the input operand
+ // for the zext will be promoted to the same width as the zext's return type
+ // rendering that zext unnecessary. This zext gets removed before the end
+ // of the pass.
if (auto ZExt = dyn_cast<ZExtInst>(I))
- if (ZExt->getType()->getScalarSizeInBits() > PromotedWidth)
+ if (ZExt->getType()->getScalarSizeInBits() >= PromotedWidth)
continue;
// Now handle the others.
diff --git a/llvm/test/Transforms/TypePromotion/AArch64/phi-zext-gep.ll b/llvm/test/Transforms/TypePromotion/AArch64/phi-zext-gep.ll
index 9c2da5a49a1b6..b24e4a10b69d1 100644
--- a/llvm/test/Transforms/TypePromotion/AArch64/phi-zext-gep.ll
+++ b/llvm/test/Transforms/TypePromotion/AArch64/phi-zext-gep.ll
@@ -24,7 +24,6 @@ define dso_local i32 @avoid_trunc_gep(i8* nocapture readonly %ip) {
; CHECK-NEXT: br label [[FOR_END]]
; CHECK: for.end:
; CHECK-NEXT: [[TAG_0_IN_LCSSA:%.*]] = phi i32 [ [[TMP0]], [[ENTRY:%.*]] ], [ [[TMP1]], [[FOR_END_LOOPEXIT]] ]
-; CHECK-NEXT: [[TMP2:%.*]] = trunc i32 [[TAG_0_IN_LCSSA]] to i8
; CHECK-NEXT: ret i32 [[TAG_0_IN_LCSSA]]
;
entry:
diff --git a/llvm/test/Transforms/TypePromotion/ARM/calls.ll b/llvm/test/Transforms/TypePromotion/ARM/calls.ll
index 9b140b029beeb..8abaa0c6646e3 100644
--- a/llvm/test/Transforms/TypePromotion/ARM/calls.ll
+++ b/llvm/test/Transforms/TypePromotion/ARM/calls.ll
@@ -216,12 +216,11 @@ define i32 @check_zext_phi_call_arg() {
; CHECK-NEXT: [[TOBOOL:%.*]] = icmp eq i32 [[D_SROA_0_0]], 0
; CHECK-NEXT: br i1 [[TOBOOL]], label [[FOR_COND_BACKEDGE]], label [[IF_THEN:%.*]]
; CHECK: for.cond.backedge:
-; CHECK-NEXT: [[D_SROA_0_0_BE]] = phi i32 [ [[TMP1:%.*]], [[IF_THEN]] ], [ 0, [[FOR_COND]] ]
+; CHECK-NEXT: [[D_SROA_0_0_BE]] = phi i32 [ [[TMP0:%.*]], [[IF_THEN]] ], [ 0, [[FOR_COND]] ]
; CHECK-NEXT: br label [[FOR_COND]]
; CHECK: if.then:
-; CHECK-NEXT: [[TMP0:%.*]] = trunc i32 [[D_SROA_0_0]] to i16
; CHECK-NEXT: [[CALL:%.*]] = tail call zeroext i16 bitcast (i16 (...)* @f to i16 (i32)*)(i32 [[D_SROA_0_0]])
-; CHECK-NEXT: [[TMP1]] = zext i16 [[CALL]] to i32
+; CHECK-NEXT: [[TMP0]] = zext i16 [[CALL]] to i32
; CHECK-NEXT: br label [[FOR_COND_BACKEDGE]]
;
entry:
diff --git a/llvm/test/Transforms/TypePromotion/ARM/casts.ll b/llvm/test/Transforms/TypePromotion/ARM/casts.ll
index 34a519fa64d60..e7b340afd746a 100644
--- a/llvm/test/Transforms/TypePromotion/ARM/casts.ll
+++ b/llvm/test/Transforms/TypePromotion/ARM/casts.ll
@@ -339,16 +339,15 @@ define i8* @two_stage_zext_trunc_mix(i32* %this, i32 %__pos1, i32 %__n1, i32** %
; CHECK-NEXT: [[CAST:%.*]] = bitcast i32** [[__SIZE__I5_I_I]] to i32*
; CHECK-NEXT: [[TMP3:%.*]] = load i32, i32* [[CAST]], align 4
; CHECK-NEXT: [[TMP4:%.*]] = lshr i32 [[TMP1]], 1
-; CHECK-NEXT: [[TMP5:%.*]] = trunc i32 [[TMP4]] to i8
; CHECK-NEXT: [[COND_I_I:%.*]] = select i1 [[TOBOOL_I_I_I_I]], i32 [[TMP4]], i32 [[TMP3]]
; CHECK-NEXT: [[__SIZE__I_I_I_I_I:%.*]] = bitcast i32* [[THIS:%.*]] to i8*
-; CHECK-NEXT: [[TMP6:%.*]] = load i8, i8* [[__SIZE__I_I_I_I_I]], align 4
-; CHECK-NEXT: [[TMP7:%.*]] = zext i8 [[TMP6]] to i32
-; CHECK-NEXT: [[TMP8:%.*]] = and i32 [[TMP7]], 1
-; CHECK-NEXT: [[TOBOOL_I_I_I_I_I:%.*]] = icmp eq i32 [[TMP8]], 0
-; CHECK-NEXT: [[TMP9:%.*]] = getelementptr inbounds i8, i8* [[__SIZE__I_I_I_I]], i32 [[__POS1:%.*]]
-; CHECK-NEXT: [[TMP10:%.*]] = getelementptr inbounds i8, i8* [[__SIZE__I_I_I_I]], i32 [[__POS2:%.*]]
-; CHECK-NEXT: [[RES:%.*]] = select i1 [[TOBOOL_I_I_I_I_I]], i8* [[TMP9]], i8* [[TMP10]]
+; CHECK-NEXT: [[TMP5:%.*]] = load i8, i8* [[__SIZE__I_I_I_I_I]], align 4
+; CHECK-NEXT: [[TMP6:%.*]] = zext i8 [[TMP5]] to i32
+; CHECK-NEXT: [[TMP7:%.*]] = and i32 [[TMP6]], 1
+; CHECK-NEXT: [[TOBOOL_I_I_I_I_I:%.*]] = icmp eq i32 [[TMP7]], 0
+; CHECK-NEXT: [[TMP8:%.*]] = getelementptr inbounds i8, i8* [[__SIZE__I_I_I_I]], i32 [[__POS1:%.*]]
+; CHECK-NEXT: [[TMP9:%.*]] = getelementptr inbounds i8, i8* [[__SIZE__I_I_I_I]], i32 [[__POS2:%.*]]
+; CHECK-NEXT: [[RES:%.*]] = select i1 [[TOBOOL_I_I_I_I_I]], i8* [[TMP8]], i8* [[TMP9]]
; CHECK-NEXT: ret i8* [[RES]]
;
entry:
@@ -1009,7 +1008,6 @@ define i32 @dont_return_inserted_trunc(i16* %a, i8* %b) {
; CHECK-NEXT: [[OR:%.*]] = or i32 [[TMP4]], [[TMP2]]
; CHECK-NEXT: [[TMP5:%.*]] = trunc i32 [[OR]] to i8
; CHECK-NEXT: store i8 [[TMP5]], i8* [[B]], align 1
-; CHECK-NEXT: [[TMP6:%.*]] = trunc i32 [[OR]] to i8
; CHECK-NEXT: ret i32 [[OR]]
;
entry:
@@ -1035,7 +1033,6 @@ define i32 @replace_trunk_with_mask(i16* %a) {
; CHECK-NEXT: [[TMP2:%.*]] = urem i32 535, [[TMP1]]
; CHECK-NEXT: [[TMP3:%.*]] = and i32 [[TMP2]], 255
; CHECK-NEXT: [[TMP4:%.*]] = udiv i32 [[TMP3]], 3
-; CHECK-NEXT: [[TMP5:%.*]] = trunc i32 [[TMP4]] to i8
; CHECK-NEXT: br label [[COND_END]]
; CHECK: cond.end:
; CHECK-NEXT: [[COND:%.*]] = phi i32 [ [[TMP4]], [[COND_FALSE]] ], [ 0, [[ENTRY:%.*]] ]
More information about the llvm-commits
mailing list