[llvm] [Transforms] Resolve FIXME: Pick the smallest legal type that fits (PR #79158)
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Fri Jan 26 08:39:51 PST 2024
https://github.com/AtariDreams updated https://github.com/llvm/llvm-project/pull/79158
>From 0f671c92a8a64265c479985449efe9978adf31df Mon Sep 17 00:00:00 2001
From: Rose <83477269+AtariDreams at users.noreply.github.com>
Date: Tue, 23 Jan 2024 10:15:46 -0500
Subject: [PATCH] [Transforms] Resolve FIXME: Pick the smallest legal type that
fits
Pick the type based on the smallest bit-width possible.
---
llvm/lib/Transforms/Scalar/Float2Int.cpp | 15 +++++--
llvm/test/Transforms/Float2Int/basic.ll | 55 ++++++++++++------------
2 files changed, 39 insertions(+), 31 deletions(-)
diff --git a/llvm/lib/Transforms/Scalar/Float2Int.cpp b/llvm/lib/Transforms/Scalar/Float2Int.cpp
index ccca8bcc1a56ac..6182259aa1c3ba 100644
--- a/llvm/lib/Transforms/Scalar/Float2Int.cpp
+++ b/llvm/lib/Transforms/Scalar/Float2Int.cpp
@@ -382,9 +382,18 @@ bool Float2IntPass::validateAndTransform() {
continue;
}
- // OK, R is known to be representable. Now pick a type for it.
- // FIXME: Pick the smallest legal type that will fit.
- Type *Ty = (MinBW > 32) ? Type::getInt64Ty(*Ctx) : Type::getInt32Ty(*Ctx);
+ // OK, R is known to be representable.
+ // Pick the smallest legal type that will fit.
+ Type *Ty;
+ if (MinBW <= 8) {
+ Ty = Type::getInt8Ty(*Ctx);
+ } else if (MinBW <= 16) {
+ Ty = Type::getInt16Ty(*Ctx);
+ } else if (MinBW <= 32) {
+ Ty = Type::getInt32Ty(*Ctx);
+ } else {
+ Ty = Type::getInt64Ty(*Ctx);
+ }
for (auto MI = ECs.member_begin(It), ME = ECs.member_end();
MI != ME; ++MI)
diff --git a/llvm/test/Transforms/Float2Int/basic.ll b/llvm/test/Transforms/Float2Int/basic.ll
index 2854a83179b7eb..aa9ef36e4caaab 100644
--- a/llvm/test/Transforms/Float2Int/basic.ll
+++ b/llvm/test/Transforms/Float2Int/basic.ll
@@ -7,10 +7,9 @@
define i16 @simple1(i8 %a) {
; CHECK-LABEL: @simple1(
-; CHECK-NEXT: [[TMP1:%.*]] = zext i8 [[A:%.*]] to i32
-; CHECK-NEXT: [[T21:%.*]] = add i32 [[TMP1]], 1
-; CHECK-NEXT: [[TMP2:%.*]] = trunc i32 [[T21]] to i16
-; CHECK-NEXT: ret i16 [[TMP2]]
+; CHECK-NEXT: [[TMP1:%.*]] = zext i8 [[A:%.*]] to i16
+; CHECK-NEXT: [[T21:%.*]] = add i16 [[TMP1]], 1
+; CHECK-NEXT: ret i16 [[T21]]
;
%t1 = uitofp i8 %a to float
%t2 = fadd float %t1, 1.0
@@ -20,9 +19,9 @@ define i16 @simple1(i8 %a) {
define i8 @simple2(i8 %a) {
; CHECK-LABEL: @simple2(
-; CHECK-NEXT: [[TMP1:%.*]] = zext i8 [[A:%.*]] to i32
-; CHECK-NEXT: [[T21:%.*]] = sub i32 [[TMP1]], 1
-; CHECK-NEXT: [[TMP2:%.*]] = trunc i32 [[T21]] to i8
+; CHECK-NEXT: [[TMP1:%.*]] = zext i8 [[A:%.*]] to i16
+; CHECK-NEXT: [[T21:%.*]] = sub i16 [[TMP1]], 1
+; CHECK-NEXT: [[TMP2:%.*]] = trunc i16 [[T21]] to i8
; CHECK-NEXT: ret i8 [[TMP2]]
;
%t1 = uitofp i8 %a to float
@@ -33,9 +32,10 @@ define i8 @simple2(i8 %a) {
define i32 @simple3(i8 %a) {
; CHECK-LABEL: @simple3(
-; CHECK-NEXT: [[TMP1:%.*]] = zext i8 [[A:%.*]] to i32
-; CHECK-NEXT: [[T21:%.*]] = sub i32 [[TMP1]], 1
-; CHECK-NEXT: ret i32 [[T21]]
+; CHECK-NEXT: [[TMP1:%.*]] = zext i8 [[A:%.*]] to i16
+; CHECK-NEXT: [[T21:%.*]] = sub i16 [[TMP1]], 1
+; CHECK-NEXT: [[TMP2:%.*]] = zext i16 [[T21]] to i32
+; CHECK-NEXT: ret i32 [[TMP2]]
;
%t1 = uitofp i8 %a to float
%t2 = fsub float %t1, 1.0
@@ -45,9 +45,9 @@ define i32 @simple3(i8 %a) {
define i1 @cmp(i8 %a, i8 %b) {
; CHECK-LABEL: @cmp(
-; CHECK-NEXT: [[TMP1:%.*]] = zext i8 [[A:%.*]] to i32
-; CHECK-NEXT: [[TMP2:%.*]] = zext i8 [[B:%.*]] to i32
-; CHECK-NEXT: [[T31:%.*]] = icmp slt i32 [[TMP1]], [[TMP2]]
+; CHECK-NEXT: [[TMP1:%.*]] = zext i8 [[A:%.*]] to i16
+; CHECK-NEXT: [[TMP2:%.*]] = zext i8 [[B:%.*]] to i16
+; CHECK-NEXT: [[T31:%.*]] = icmp slt i16 [[TMP1]], [[TMP2]]
; CHECK-NEXT: ret i1 [[T31]]
;
%t1 = uitofp i8 %a to float
@@ -106,13 +106,14 @@ define i32 @simple6(i8 %a, i8 %b) {
define i32 @multi1(i8 %a, i8 %b, i8 %c, float %d) {
; CHECK-LABEL: @multi1(
-; CHECK-NEXT: [[TMP1:%.*]] = zext i8 [[A:%.*]] to i32
-; CHECK-NEXT: [[TMP2:%.*]] = zext i8 [[B:%.*]] to i32
+; CHECK-NEXT: [[TMP1:%.*]] = zext i8 [[A:%.*]] to i16
+; CHECK-NEXT: [[TMP2:%.*]] = zext i8 [[B:%.*]] to i16
; CHECK-NEXT: [[FC:%.*]] = uitofp i8 [[C:%.*]] to float
-; CHECK-NEXT: [[X1:%.*]] = add i32 [[TMP1]], [[TMP2]]
+; CHECK-NEXT: [[X1:%.*]] = add i16 [[TMP1]], [[TMP2]]
+; CHECK-NEXT: [[TMP3:%.*]] = zext i16 [[X1]] to i32
; CHECK-NEXT: [[Z:%.*]] = fadd float [[FC]], [[D:%.*]]
; CHECK-NEXT: [[W:%.*]] = fptoui float [[Z]] to i32
-; CHECK-NEXT: [[R:%.*]] = add i32 [[X1]], [[W]]
+; CHECK-NEXT: [[R:%.*]] = add i32 [[TMP3]], [[W]]
; CHECK-NEXT: ret i32 [[R]]
;
%fa = uitofp i8 %a to float
@@ -128,10 +129,9 @@ define i32 @multi1(i8 %a, i8 %b, i8 %c, float %d) {
define i16 @simple_negzero(i8 %a) {
; CHECK-LABEL: @simple_negzero(
-; CHECK-NEXT: [[TMP1:%.*]] = zext i8 [[A:%.*]] to i32
-; CHECK-NEXT: [[T21:%.*]] = add i32 [[TMP1]], 0
-; CHECK-NEXT: [[TMP2:%.*]] = trunc i32 [[T21]] to i16
-; CHECK-NEXT: ret i16 [[TMP2]]
+; CHECK-NEXT: [[TMP1:%.*]] = zext i8 [[A:%.*]] to i16
+; CHECK-NEXT: [[T21:%.*]] = add i16 [[TMP1]], 0
+; CHECK-NEXT: ret i16 [[T21]]
;
%t1 = uitofp i8 %a to float
%t2 = fadd fast float %t1, -0.0
@@ -141,9 +141,9 @@ define i16 @simple_negzero(i8 %a) {
define i32 @simple_negative(i8 %call) {
; CHECK-LABEL: @simple_negative(
-; CHECK-NEXT: [[TMP1:%.*]] = sext i8 [[CALL:%.*]] to i32
-; CHECK-NEXT: [[MUL1:%.*]] = mul i32 [[TMP1]], -3
-; CHECK-NEXT: [[TMP2:%.*]] = trunc i32 [[MUL1]] to i8
+; CHECK-NEXT: [[TMP1:%.*]] = sext i8 [[CALL:%.*]] to i16
+; CHECK-NEXT: [[MUL1:%.*]] = mul i16 [[TMP1]], -3
+; CHECK-NEXT: [[TMP2:%.*]] = trunc i16 [[MUL1]] to i8
; CHECK-NEXT: [[CONV3:%.*]] = sext i8 [[TMP2]] to i32
; CHECK-NEXT: ret i32 [[CONV3]]
;
@@ -156,10 +156,9 @@ define i32 @simple_negative(i8 %call) {
define i16 @simple_fneg(i8 %a) {
; CHECK-LABEL: @simple_fneg(
-; CHECK-NEXT: [[TMP1:%.*]] = zext i8 [[A:%.*]] to i32
-; CHECK-NEXT: [[T21:%.*]] = sub i32 0, [[TMP1]]
-; CHECK-NEXT: [[TMP2:%.*]] = trunc i32 [[T21]] to i16
-; CHECK-NEXT: ret i16 [[TMP2]]
+; CHECK-NEXT: [[TMP1:%.*]] = zext i8 [[A:%.*]] to i16
+; CHECK-NEXT: [[T21:%.*]] = sub i16 0, [[TMP1]]
+; CHECK-NEXT: ret i16 [[T21]]
;
%t1 = uitofp i8 %a to float
%t2 = fneg fast float %t1
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