From: Simon Atanasyan <simon@atanasyan.com>
Date: Fri, 24 May 2019 08:39:40 +0000 (+0000)
Subject: [mips] Always check that `shift and add` optimization is efficient.
X-Git-Url: https://granicus.if.org/sourcecode?a=commitdiff_plain;h=81f980568b9b3df33e427896a2a7881cba83f946;p=llvm

[mips] Always check that `shift and add` optimization is efficient.

The D45316 introduced the `shouldTransformMulToShiftsAddsSubs` function
to check that breaking down constant multiplications into a series
of shifts, adds, and subs is efficient. Unfortunately, this function
does not check maximum number of steps on all paths of the algorithm.
This patch fixes this bug.

Fix for PR41929.

Differential Revision: https://reviews.llvm.org/D62166

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@361606 91177308-0d34-0410-b5e6-96231b3b80d8
---

diff --git a/lib/Target/Mips/MipsSEISelLowering.cpp b/lib/Target/Mips/MipsSEISelLowering.cpp
index 6fbdba4c691..2fe2f1694f1 100644
--- a/lib/Target/Mips/MipsSEISelLowering.cpp
+++ b/lib/Target/Mips/MipsSEISelLowering.cpp
@@ -719,8 +719,31 @@ static bool shouldTransformMulToShiftsAddsSubs(APInt C, EVT VT,
                                                SelectionDAG &DAG,
                                                const MipsSubtarget &Subtarget) {
   // Estimate the number of operations the below transform will turn a
-  // constant multiply into. The number is approximately how many powers
-  // of two summed together that the constant can be broken down into.
+  // constant multiply into. The number is approximately equal to the minimal
+  // number of powers of two that constant can be broken down to by adding
+  // or subtracting them.
+  //
+  // If we have taken more than 12[1] / 8[2] steps to attempt the
+  // optimization for a native sized value, it is more than likely that this
+  // optimization will make things worse.
+  //
+  // [1] MIPS64 requires 6 instructions at most to materialize any constant,
+  //     multiplication requires at least 4 cycles, but another cycle (or two)
+  //     to retrieve the result from the HI/LO registers.
+  //
+  // [2] For MIPS32, more than 8 steps is expensive as the constant could be
+  //     materialized in 2 instructions, multiplication requires at least 4
+  //     cycles, but another cycle (or two) to retrieve the result from the
+  //     HI/LO registers.
+  //
+  // TODO:
+  // - MaxSteps needs to consider the `VT` of the constant for the current
+  //   target.
+  // - Consider to perform this optimization after type legalization.
+  //   That allows to remove a workaround for types not supported natively.
+  // - Take in account `-Os, -Oz` flags because this optimization
+  //   increases code size.
+  unsigned MaxSteps = Subtarget.isABI_O32() ? 8 : 12;
 
   SmallVector<APInt, 16> WorkStack(1, C);
   unsigned Steps = 0;
@@ -732,6 +755,9 @@ static bool shouldTransformMulToShiftsAddsSubs(APInt C, EVT VT,
     if (Val == 0 || Val == 1)
       continue;
 
+    if (Steps >= MaxSteps)
+      return false;
+
     if (Val.isPowerOf2()) {
       ++Steps;
       continue;
@@ -740,36 +766,15 @@ static bool shouldTransformMulToShiftsAddsSubs(APInt C, EVT VT,
     APInt Floor = APInt(BitWidth, 1) << Val.logBase2();
     APInt Ceil = Val.isNegative() ? APInt(BitWidth, 0)
                                   : APInt(BitWidth, 1) << C.ceilLogBase2();
-
     if ((Val - Floor).ule(Ceil - Val)) {
       WorkStack.push_back(Floor);
       WorkStack.push_back(Val - Floor);
-      ++Steps;
-      continue;
+    } else {
+      WorkStack.push_back(Ceil);
+      WorkStack.push_back(Ceil - Val);
     }
 
-    WorkStack.push_back(Ceil);
-    WorkStack.push_back(Ceil - Val);
     ++Steps;
-
-    // If we have taken more than 12[1] / 8[2] steps to attempt the
-    // optimization for a native sized value, it is more than likely that this
-    // optimization will make things worse.
-    //
-    // [1] MIPS64 requires 6 instructions at most to materialize any constant,
-    //     multiplication requires at least 4 cycles, but another cycle (or two)
-    //     to retrieve the result from the HI/LO registers.
-    //
-    // [2] For MIPS32, more than 8 steps is expensive as the constant could be
-    //     materialized in 2 instructions, multiplication requires at least 4
-    //     cycles, but another cycle (or two) to retrieve the result from the
-    //     HI/LO registers.
-
-    if (Steps > 12 && (Subtarget.isABI_N32() || Subtarget.isABI_N64()))
-      return false;
-
-    if (Steps > 8 && Subtarget.isABI_O32())
-      return false;
   }
 
   // If the value being multiplied is not supported natively, we have to pay
diff --git a/test/CodeGen/Mips/const-mult.ll b/test/CodeGen/Mips/const-mult.ll
index cbb3c91299f..dd90971dcee 100644
--- a/test/CodeGen/Mips/const-mult.ll
+++ b/test/CodeGen/Mips/const-mult.ll
@@ -212,44 +212,18 @@ entry:
 define i32 @mul42949673_32(i32 %a) {
 ; MIPS32-LABEL: mul42949673_32:
 ; MIPS32:       # %bb.0:
-; MIPS32-NEXT:    sll $1, $4, 3
-; MIPS32-NEXT:    addu $1, $1, $4
-; MIPS32-NEXT:    sll $2, $4, 5
-; MIPS32-NEXT:    addu $1, $2, $1
-; MIPS32-NEXT:    sll $2, $4, 10
-; MIPS32-NEXT:    subu $1, $2, $1
-; MIPS32-NEXT:    sll $2, $4, 13
-; MIPS32-NEXT:    addu $1, $2, $1
-; MIPS32-NEXT:    sll $2, $4, 15
-; MIPS32-NEXT:    addu $1, $2, $1
-; MIPS32-NEXT:    sll $2, $4, 20
-; MIPS32-NEXT:    subu $1, $2, $1
-; MIPS32-NEXT:    sll $2, $4, 25
-; MIPS32-NEXT:    sll $3, $4, 23
-; MIPS32-NEXT:    addu $1, $3, $1
+; MIPS32-NEXT:    lui $1, 655
+; MIPS32-NEXT:    ori $1, $1, 23593
 ; MIPS32-NEXT:    jr $ra
-; MIPS32-NEXT:    addu $2, $2, $1
+; MIPS32-NEXT:    mul $2, $4, $1
 ;
 ; MIPS64-LABEL: mul42949673_32:
 ; MIPS64:       # %bb.0:
-; MIPS64-NEXT:    sll $1, $4, 0
-; MIPS64-NEXT:    sll $2, $1, 3
-; MIPS64-NEXT:    addu $2, $2, $1
-; MIPS64-NEXT:    sll $3, $1, 5
-; MIPS64-NEXT:    addu $2, $3, $2
-; MIPS64-NEXT:    sll $3, $1, 10
-; MIPS64-NEXT:    subu $2, $3, $2
-; MIPS64-NEXT:    sll $3, $1, 13
-; MIPS64-NEXT:    addu $2, $3, $2
-; MIPS64-NEXT:    sll $3, $1, 15
-; MIPS64-NEXT:    addu $2, $3, $2
-; MIPS64-NEXT:    sll $3, $1, 20
-; MIPS64-NEXT:    subu $2, $3, $2
-; MIPS64-NEXT:    sll $3, $1, 25
-; MIPS64-NEXT:    sll $1, $1, 23
-; MIPS64-NEXT:    addu $1, $1, $2
+; MIPS64-NEXT:    lui $1, 655
+; MIPS64-NEXT:    ori $1, $1, 23593
+; MIPS64-NEXT:    sll $2, $4, 0
 ; MIPS64-NEXT:    jr $ra
-; MIPS64-NEXT:    addu $2, $3, $1
+; MIPS64-NEXT:    mul $2, $2, $1
   %b = mul i32 %a, 42949673
   ret i32 %b
 }
@@ -261,45 +235,18 @@ define i64 @mul42949673_64(i64 %a) {
 ; MIPS32-NEXT:    ori $1, $1, 23593
 ; MIPS32-NEXT:    multu $4, $1
 ; MIPS32-NEXT:    mflo $2
-; MIPS32-NEXT:    mfhi $1
-; MIPS32-NEXT:    sll $3, $5, 3
-; MIPS32-NEXT:    addu $3, $3, $5
-; MIPS32-NEXT:    sll $4, $5, 5
-; MIPS32-NEXT:    addu $3, $4, $3
-; MIPS32-NEXT:    sll $4, $5, 10
-; MIPS32-NEXT:    subu $3, $4, $3
-; MIPS32-NEXT:    sll $4, $5, 13
-; MIPS32-NEXT:    addu $3, $4, $3
-; MIPS32-NEXT:    sll $4, $5, 15
-; MIPS32-NEXT:    addu $3, $4, $3
-; MIPS32-NEXT:    sll $4, $5, 20
-; MIPS32-NEXT:    subu $3, $4, $3
-; MIPS32-NEXT:    sll $4, $5, 25
-; MIPS32-NEXT:    sll $5, $5, 23
-; MIPS32-NEXT:    addu $3, $5, $3
-; MIPS32-NEXT:    addu $3, $4, $3
+; MIPS32-NEXT:    mfhi $3
+; MIPS32-NEXT:    mul $1, $5, $1
 ; MIPS32-NEXT:    jr $ra
-; MIPS32-NEXT:    addu $3, $1, $3
+; MIPS32-NEXT:    addu $3, $3, $1
 ;
 ; MIPS64-LABEL: mul42949673_64:
 ; MIPS64:       # %bb.0: # %entry
-; MIPS64-NEXT:    dsll $1, $4, 3
-; MIPS64-NEXT:    daddu $1, $1, $4
-; MIPS64-NEXT:    dsll $2, $4, 5
-; MIPS64-NEXT:    daddu $1, $2, $1
-; MIPS64-NEXT:    dsll $2, $4, 10
-; MIPS64-NEXT:    dsubu $1, $2, $1
-; MIPS64-NEXT:    dsll $2, $4, 13
-; MIPS64-NEXT:    daddu $1, $2, $1
-; MIPS64-NEXT:    dsll $2, $4, 15
-; MIPS64-NEXT:    daddu $1, $2, $1
-; MIPS64-NEXT:    dsll $2, $4, 20
-; MIPS64-NEXT:    dsubu $1, $2, $1
-; MIPS64-NEXT:    dsll $2, $4, 25
-; MIPS64-NEXT:    dsll $3, $4, 23
-; MIPS64-NEXT:    daddu $1, $3, $1
+; MIPS64-NEXT:    lui $1, 655
+; MIPS64-NEXT:    ori $1, $1, 23593
+; MIPS64-NEXT:    dmult $4, $1
 ; MIPS64-NEXT:    jr $ra
-; MIPS64-NEXT:    daddu $2, $2, $1
+; MIPS64-NEXT:    mflo $2
 entry:
   %b = mul i64 %a, 42949673
   ret i64 %b
@@ -308,54 +255,18 @@ entry:
 define i32 @mul22224078_32(i32 %a) {
 ; MIPS32-LABEL: mul22224078_32:
 ; MIPS32:       # %bb.0: # %entry
-; MIPS32-NEXT:    sll $1, $4, 1
-; MIPS32-NEXT:    sll $2, $4, 4
-; MIPS32-NEXT:    subu $1, $2, $1
-; MIPS32-NEXT:    sll $2, $4, 6
-; MIPS32-NEXT:    subu $1, $1, $2
-; MIPS32-NEXT:    sll $2, $4, 8
-; MIPS32-NEXT:    addu $1, $2, $1
-; MIPS32-NEXT:    sll $2, $4, 10
-; MIPS32-NEXT:    subu $1, $1, $2
-; MIPS32-NEXT:    sll $2, $4, 13
-; MIPS32-NEXT:    addu $1, $2, $1
-; MIPS32-NEXT:    sll $2, $4, 16
-; MIPS32-NEXT:    subu $1, $1, $2
-; MIPS32-NEXT:    sll $2, $4, 24
-; MIPS32-NEXT:    sll $3, $4, 22
-; MIPS32-NEXT:    sll $5, $4, 20
-; MIPS32-NEXT:    sll $4, $4, 18
-; MIPS32-NEXT:    addu $1, $4, $1
-; MIPS32-NEXT:    addu $1, $5, $1
-; MIPS32-NEXT:    addu $1, $3, $1
+; MIPS32-NEXT:    lui $1, 339
+; MIPS32-NEXT:    ori $1, $1, 7374
 ; MIPS32-NEXT:    jr $ra
-; MIPS32-NEXT:    addu $2, $2, $1
+; MIPS32-NEXT:    mul $2, $4, $1
 ;
 ; MIPS64-LABEL: mul22224078_32:
 ; MIPS64:       # %bb.0: # %entry
-; MIPS64-NEXT:    sll $1, $4, 0
-; MIPS64-NEXT:    sll $2, $1, 1
-; MIPS64-NEXT:    sll $3, $1, 4
-; MIPS64-NEXT:    subu $2, $3, $2
-; MIPS64-NEXT:    sll $3, $1, 6
-; MIPS64-NEXT:    subu $2, $2, $3
-; MIPS64-NEXT:    sll $3, $1, 8
-; MIPS64-NEXT:    addu $2, $3, $2
-; MIPS64-NEXT:    sll $3, $1, 10
-; MIPS64-NEXT:    subu $2, $2, $3
-; MIPS64-NEXT:    sll $3, $1, 13
-; MIPS64-NEXT:    addu $2, $3, $2
-; MIPS64-NEXT:    sll $3, $1, 16
-; MIPS64-NEXT:    subu $2, $2, $3
-; MIPS64-NEXT:    sll $3, $1, 24
-; MIPS64-NEXT:    sll $4, $1, 22
-; MIPS64-NEXT:    sll $5, $1, 20
-; MIPS64-NEXT:    sll $1, $1, 18
-; MIPS64-NEXT:    addu $1, $1, $2
-; MIPS64-NEXT:    addu $1, $5, $1
-; MIPS64-NEXT:    addu $1, $4, $1
+; MIPS64-NEXT:    lui $1, 339
+; MIPS64-NEXT:    ori $1, $1, 7374
+; MIPS64-NEXT:    sll $2, $4, 0
 ; MIPS64-NEXT:    jr $ra
-; MIPS64-NEXT:    addu $2, $3, $1
+; MIPS64-NEXT:    mul $2, $2, $1
 entry:
   %b = mul i32 %a, 22224078
   ret i32 %b
@@ -368,55 +279,18 @@ define i64 @mul22224078_64(i64 %a) {
 ; MIPS32-NEXT:    ori $1, $1, 7374
 ; MIPS32-NEXT:    multu $4, $1
 ; MIPS32-NEXT:    mflo $2
-; MIPS32-NEXT:    mfhi $1
-; MIPS32-NEXT:    sll $3, $5, 1
-; MIPS32-NEXT:    sll $4, $5, 4
-; MIPS32-NEXT:    subu $3, $4, $3
-; MIPS32-NEXT:    sll $4, $5, 6
-; MIPS32-NEXT:    subu $3, $3, $4
-; MIPS32-NEXT:    sll $4, $5, 8
-; MIPS32-NEXT:    addu $3, $4, $3
-; MIPS32-NEXT:    sll $4, $5, 10
-; MIPS32-NEXT:    subu $3, $3, $4
-; MIPS32-NEXT:    sll $4, $5, 13
-; MIPS32-NEXT:    addu $3, $4, $3
-; MIPS32-NEXT:    sll $4, $5, 16
-; MIPS32-NEXT:    subu $3, $3, $4
-; MIPS32-NEXT:    sll $4, $5, 24
-; MIPS32-NEXT:    sll $6, $5, 22
-; MIPS32-NEXT:    sll $7, $5, 20
-; MIPS32-NEXT:    sll $5, $5, 18
-; MIPS32-NEXT:    addu $3, $5, $3
-; MIPS32-NEXT:    addu $3, $7, $3
-; MIPS32-NEXT:    addu $3, $6, $3
-; MIPS32-NEXT:    addu $3, $4, $3
+; MIPS32-NEXT:    mfhi $3
+; MIPS32-NEXT:    mul $1, $5, $1
 ; MIPS32-NEXT:    jr $ra
-; MIPS32-NEXT:    addu $3, $1, $3
+; MIPS32-NEXT:    addu $3, $3, $1
 ;
 ; MIPS64-LABEL: mul22224078_64:
 ; MIPS64:       # %bb.0: # %entry
-; MIPS64-NEXT:    dsll $1, $4, 1
-; MIPS64-NEXT:    dsll $2, $4, 4
-; MIPS64-NEXT:    dsubu $1, $2, $1
-; MIPS64-NEXT:    dsll $2, $4, 6
-; MIPS64-NEXT:    dsubu $1, $1, $2
-; MIPS64-NEXT:    dsll $2, $4, 8
-; MIPS64-NEXT:    daddu $1, $2, $1
-; MIPS64-NEXT:    dsll $2, $4, 10
-; MIPS64-NEXT:    dsubu $1, $1, $2
-; MIPS64-NEXT:    dsll $2, $4, 13
-; MIPS64-NEXT:    daddu $1, $2, $1
-; MIPS64-NEXT:    dsll $2, $4, 16
-; MIPS64-NEXT:    dsubu $1, $1, $2
-; MIPS64-NEXT:    dsll $2, $4, 24
-; MIPS64-NEXT:    dsll $3, $4, 22
-; MIPS64-NEXT:    dsll $5, $4, 20
-; MIPS64-NEXT:    dsll $4, $4, 18
-; MIPS64-NEXT:    daddu $1, $4, $1
-; MIPS64-NEXT:    daddu $1, $5, $1
-; MIPS64-NEXT:    daddu $1, $3, $1
+; MIPS64-NEXT:    lui $1, 339
+; MIPS64-NEXT:    ori $1, $1, 7374
+; MIPS64-NEXT:    dmult $4, $1
 ; MIPS64-NEXT:    jr $ra
-; MIPS64-NEXT:    daddu $2, $2, $1
+; MIPS64-NEXT:    mflo $2
 entry:
   %b = mul i64 %a, 22224078
   ret i64 %b
@@ -425,36 +299,18 @@ entry:
 define i32 @mul22245375_32(i32 %a) {
 ; MIPS32-LABEL: mul22245375_32:
 ; MIPS32:       # %bb.0: # %entry
-; MIPS32-NEXT:    sll $1, $4, 12
-; MIPS32-NEXT:    addu $1, $1, $4
-; MIPS32-NEXT:    sll $2, $4, 15
-; MIPS32-NEXT:    addu $1, $2, $1
-; MIPS32-NEXT:    sll $2, $4, 18
-; MIPS32-NEXT:    subu $1, $2, $1
-; MIPS32-NEXT:    sll $2, $4, 20
-; MIPS32-NEXT:    addu $1, $2, $1
-; MIPS32-NEXT:    sll $2, $4, 22
-; MIPS32-NEXT:    addu $1, $2, $1
-; MIPS32-NEXT:    sll $2, $4, 24
+; MIPS32-NEXT:    lui $1, 339
+; MIPS32-NEXT:    ori $1, $1, 28671
 ; MIPS32-NEXT:    jr $ra
-; MIPS32-NEXT:    addu $2, $2, $1
+; MIPS32-NEXT:    mul $2, $4, $1
 ;
 ; MIPS64-LABEL: mul22245375_32:
 ; MIPS64:       # %bb.0: # %entry
-; MIPS64-NEXT:    sll $1, $4, 0
-; MIPS64-NEXT:    sll $2, $1, 12
-; MIPS64-NEXT:    addu $2, $2, $1
-; MIPS64-NEXT:    sll $3, $1, 15
-; MIPS64-NEXT:    addu $2, $3, $2
-; MIPS64-NEXT:    sll $3, $1, 18
-; MIPS64-NEXT:    subu $2, $3, $2
-; MIPS64-NEXT:    sll $3, $1, 20
-; MIPS64-NEXT:    addu $2, $3, $2
-; MIPS64-NEXT:    sll $3, $1, 22
-; MIPS64-NEXT:    addu $2, $3, $2
-; MIPS64-NEXT:    sll $1, $1, 24
+; MIPS64-NEXT:    lui $1, 339
+; MIPS64-NEXT:    ori $1, $1, 28671
+; MIPS64-NEXT:    sll $2, $4, 0
 ; MIPS64-NEXT:    jr $ra
-; MIPS64-NEXT:    addu $2, $1, $2
+; MIPS64-NEXT:    mul $2, $2, $1
 entry:
   %b = mul i32 %a, 22245375
   ret i32 %b
@@ -467,37 +323,18 @@ define i64 @mul22245375_64(i64 %a) {
 ; MIPS32-NEXT:    ori $1, $1, 28671
 ; MIPS32-NEXT:    multu $4, $1
 ; MIPS32-NEXT:    mflo $2
-; MIPS32-NEXT:    mfhi $1
-; MIPS32-NEXT:    sll $3, $5, 12
-; MIPS32-NEXT:    addu $3, $3, $5
-; MIPS32-NEXT:    sll $4, $5, 15
-; MIPS32-NEXT:    addu $3, $4, $3
-; MIPS32-NEXT:    sll $4, $5, 18
-; MIPS32-NEXT:    subu $3, $4, $3
-; MIPS32-NEXT:    sll $4, $5, 20
-; MIPS32-NEXT:    addu $3, $4, $3
-; MIPS32-NEXT:    sll $4, $5, 22
-; MIPS32-NEXT:    addu $3, $4, $3
-; MIPS32-NEXT:    sll $4, $5, 24
-; MIPS32-NEXT:    addu $3, $4, $3
+; MIPS32-NEXT:    mfhi $3
+; MIPS32-NEXT:    mul $1, $5, $1
 ; MIPS32-NEXT:    jr $ra
-; MIPS32-NEXT:    addu $3, $1, $3
+; MIPS32-NEXT:    addu $3, $3, $1
 ;
 ; MIPS64-LABEL: mul22245375_64:
 ; MIPS64:       # %bb.0: # %entry
-; MIPS64-NEXT:    dsll $1, $4, 12
-; MIPS64-NEXT:    daddu $1, $1, $4
-; MIPS64-NEXT:    dsll $2, $4, 15
-; MIPS64-NEXT:    daddu $1, $2, $1
-; MIPS64-NEXT:    dsll $2, $4, 18
-; MIPS64-NEXT:    dsubu $1, $2, $1
-; MIPS64-NEXT:    dsll $2, $4, 20
-; MIPS64-NEXT:    daddu $1, $2, $1
-; MIPS64-NEXT:    dsll $2, $4, 22
-; MIPS64-NEXT:    daddu $1, $2, $1
-; MIPS64-NEXT:    dsll $2, $4, 24
+; MIPS64-NEXT:    lui $1, 339
+; MIPS64-NEXT:    ori $1, $1, 28671
+; MIPS64-NEXT:    dmult $4, $1
 ; MIPS64-NEXT:    jr $ra
-; MIPS64-NEXT:    daddu $2, $2, $1
+; MIPS64-NEXT:    mflo $2
 entry:
   %b = mul i64 %a, 22245375
   ret i64 %b
@@ -506,36 +343,18 @@ entry:
 define i32 @mul25165824_32(i32 %a) {
 ; MIPS32-LABEL: mul25165824_32:
 ; MIPS32:       # %bb.0: # %entry
-; MIPS32-NEXT:    sll $1, $4, 12
-; MIPS32-NEXT:    addu $1, $1, $4
-; MIPS32-NEXT:    sll $2, $4, 15
-; MIPS32-NEXT:    addu $1, $2, $1
-; MIPS32-NEXT:    sll $2, $4, 18
-; MIPS32-NEXT:    subu $1, $2, $1
-; MIPS32-NEXT:    sll $2, $4, 20
-; MIPS32-NEXT:    addu $1, $2, $1
-; MIPS32-NEXT:    sll $2, $4, 22
-; MIPS32-NEXT:    addu $1, $2, $1
-; MIPS32-NEXT:    sll $2, $4, 24
+; MIPS32-NEXT:    lui $1, 339
+; MIPS32-NEXT:    ori $1, $1, 28671
 ; MIPS32-NEXT:    jr $ra
-; MIPS32-NEXT:    addu $2, $2, $1
+; MIPS32-NEXT:    mul $2, $4, $1
 ;
 ; MIPS64-LABEL: mul25165824_32:
 ; MIPS64:       # %bb.0: # %entry
-; MIPS64-NEXT:    sll $1, $4, 0
-; MIPS64-NEXT:    sll $2, $1, 12
-; MIPS64-NEXT:    addu $2, $2, $1
-; MIPS64-NEXT:    sll $3, $1, 15
-; MIPS64-NEXT:    addu $2, $3, $2
-; MIPS64-NEXT:    sll $3, $1, 18
-; MIPS64-NEXT:    subu $2, $3, $2
-; MIPS64-NEXT:    sll $3, $1, 20
-; MIPS64-NEXT:    addu $2, $3, $2
-; MIPS64-NEXT:    sll $3, $1, 22
-; MIPS64-NEXT:    addu $2, $3, $2
-; MIPS64-NEXT:    sll $1, $1, 24
+; MIPS64-NEXT:    lui $1, 339
+; MIPS64-NEXT:    ori $1, $1, 28671
+; MIPS64-NEXT:    sll $2, $4, 0
 ; MIPS64-NEXT:    jr $ra
-; MIPS64-NEXT:    addu $2, $1, $2
+; MIPS64-NEXT:    mul $2, $2, $1
 entry:
   %b = mul i32 %a, 22245375
   ret i32 %b
@@ -572,36 +391,18 @@ entry:
 define i32 @mul33554432_32(i32 %a) {
 ; MIPS32-LABEL: mul33554432_32:
 ; MIPS32:       # %bb.0: # %entry
-; MIPS32-NEXT:    sll $1, $4, 12
-; MIPS32-NEXT:    addu $1, $1, $4
-; MIPS32-NEXT:    sll $2, $4, 15
-; MIPS32-NEXT:    addu $1, $2, $1
-; MIPS32-NEXT:    sll $2, $4, 18
-; MIPS32-NEXT:    subu $1, $2, $1
-; MIPS32-NEXT:    sll $2, $4, 20
-; MIPS32-NEXT:    addu $1, $2, $1
-; MIPS32-NEXT:    sll $2, $4, 22
-; MIPS32-NEXT:    addu $1, $2, $1
-; MIPS32-NEXT:    sll $2, $4, 24
+; MIPS32-NEXT:    lui $1, 339
+; MIPS32-NEXT:    ori $1, $1, 28671
 ; MIPS32-NEXT:    jr $ra
-; MIPS32-NEXT:    addu $2, $2, $1
+; MIPS32-NEXT:    mul $2, $4, $1
 ;
 ; MIPS64-LABEL: mul33554432_32:
 ; MIPS64:       # %bb.0: # %entry
-; MIPS64-NEXT:    sll $1, $4, 0
-; MIPS64-NEXT:    sll $2, $1, 12
-; MIPS64-NEXT:    addu $2, $2, $1
-; MIPS64-NEXT:    sll $3, $1, 15
-; MIPS64-NEXT:    addu $2, $3, $2
-; MIPS64-NEXT:    sll $3, $1, 18
-; MIPS64-NEXT:    subu $2, $3, $2
-; MIPS64-NEXT:    sll $3, $1, 20
-; MIPS64-NEXT:    addu $2, $3, $2
-; MIPS64-NEXT:    sll $3, $1, 22
-; MIPS64-NEXT:    addu $2, $3, $2
-; MIPS64-NEXT:    sll $1, $1, 24
+; MIPS64-NEXT:    lui $1, 339
+; MIPS64-NEXT:    ori $1, $1, 28671
+; MIPS64-NEXT:    sll $2, $4, 0
 ; MIPS64-NEXT:    jr $ra
-; MIPS64-NEXT:    addu $2, $1, $2
+; MIPS64-NEXT:    mul $2, $2, $1
 entry:
   %b = mul i32 %a, 22245375
   ret i32 %b