Apply upstream: [mips] Trap on integer division by zero.

Cherry-pick r182306 from upstream.

Original commit message:

Author: Akira Hatanaka <ahatanaka@mips.com>
Date:   Mon May 20 18:07:43 2013 +0000

[mips] Trap on integer division by zero.

By default, a teq instruction is inserted after integer divide. No divide-by-zero
checks are performed if option "-mnocheck-zero-division" is used.

TBR= mseaborn@chromium.org, dschuff@chromium.org
BUG= missing trap for MIPS

Review URL: https://codereview.chromium.org/26846007

2 files changed, 41 insertions, 11 deletions

diff --git a/test/CodeGen/Mips/divrem.ll b/test/CodeGen/Mips/divrem.ll
index c470d1ce2c..d221501a31 100644
--- a/test/CodeGen/Mips/divrem.ll
+++ b/test/CodeGen/Mips/divrem.ll
@@ -1,34 +1,56 @@
-; RUN: llc -march=mips < %s | FileCheck %s
+; RUN: llc -march=mips < %s | FileCheck %s -check-prefix=TRAP
+; RUN: llc -march=mips -mnocheck-zero-division < %s |\
+; RUN: FileCheck %s -check-prefix=NOCHECK
+
+; TRAP: sdiv1:
+; TRAP: div $zero, ${{[0-9]+}}, $[[R0:[0-9]+]]
+; TRAP: teq $[[R0]], $zero, 7
+; TRAP: mflo
+
+; NOCHECK: sdiv1:
+; NOCHECK-NOT: teq
+; NOCHECK: .end sdiv1
 
-; CHECK: div $zero,
 define i32 @sdiv1(i32 %a0, i32 %a1) nounwind readnone {
 entry:
   %div = sdiv i32 %a0, %a1
   ret i32 %div
 }
 
-; CHECK: div $zero,
+; TRAP: srem1:
+; TRAP: div $zero, ${{[0-9]+}}, $[[R0:[0-9]+]]
+; TRAP: teq $[[R0]], $zero, 7
+; TRAP: mfhi
+
 define i32 @srem1(i32 %a0, i32 %a1) nounwind readnone {
 entry:
   %rem = srem i32 %a0, %a1
   ret i32 %rem
 }
 
-; CHECK: divu $zero,
+; TRAP: udiv1:
+; TRAP: divu $zero, ${{[0-9]+}}, $[[R0:[0-9]+]]
+; TRAP: teq $[[R0]], $zero, 7
+; TRAP: mflo
+
 define i32 @udiv1(i32 %a0, i32 %a1) nounwind readnone {
 entry:
   %div = udiv i32 %a0, %a1
   ret i32 %div
 }
 
-; CHECK: divu $zero,
+; TRAP: urem1:
+; TRAP: divu $zero, ${{[0-9]+}}, $[[R0:[0-9]+]]
+; TRAP: teq $[[R0]], $zero, 7
+; TRAP: mfhi
+
 define i32 @urem1(i32 %a0, i32 %a1) nounwind readnone {
 entry:
   %rem = urem i32 %a0, %a1
   ret i32 %rem
 }
 
-; CHECK: div $zero,
+; TRAP: div $zero,
 define i32 @sdivrem1(i32 %a0, i32 %a1, i32* nocapture %r) nounwind {
 entry:
   %rem = srem i32 %a0, %a1
@@ -37,7 +59,7 @@ entry:
   ret i32 %div
 }
 
-; CHECK: divu $zero,
+; TRAP: divu $zero,
 define i32 @udivrem1(i32 %a0, i32 %a1, i32* nocapture %r) nounwind {
 entry:
   %rem = urem i32 %a0, %a1
diff --git a/test/CodeGen/Mips/mips64instrs.ll b/test/CodeGen/Mips/mips64instrs.ll
index 0418311490..2e3df3a0a8 100644
--- a/test/CodeGen/Mips/mips64instrs.ll
+++ b/test/CodeGen/Mips/mips64instrs.ll
@@ -86,7 +86,9 @@ entry:
 
 define i64 @f14(i64 %a, i64 %b) nounwind readnone {
 entry:
-; CHECK: ddiv $zero
+; CHECK: f14:
+; CHECK: ddiv $zero, ${{[0-9]+}}, $[[R0:[0-9]+]]
+; CHECK: teq $[[R0]], $zero, 7
 ; CHECK: mflo
   %div = sdiv i64 %a, %b
   ret i64 %div
@@ -94,7 +96,9 @@ entry:
 
 define i64 @f15(i64 %a, i64 %b) nounwind readnone {
 entry:
-; CHECK: ddivu $zero
+; CHECK: f15:
+; CHECK: ddivu $zero, ${{[0-9]+}}, $[[R0:[0-9]+]]
+; CHECK: teq $[[R0]], $zero, 7
 ; CHECK: mflo
   %div = udiv i64 %a, %b
   ret i64 %div
@@ -102,7 +106,9 @@ entry:
 
 define i64 @f16(i64 %a, i64 %b) nounwind readnone {
 entry:
-; CHECK: ddiv $zero
+; CHECK: f16:
+; CHECK: ddiv $zero, ${{[0-9]+}}, $[[R0:[0-9]+]]
+; CHECK: teq $[[R0]], $zero, 7
 ; CHECK: mfhi
   %rem = srem i64 %a, %b
   ret i64 %rem
@@ -110,7 +116,9 @@ entry:
 
 define i64 @f17(i64 %a, i64 %b) nounwind readnone {
 entry:
-; CHECK: ddivu $zero
+; CHECK: f17:
+; CHECK: ddivu $zero, ${{[0-9]+}}, $[[R0:[0-9]+]]
+; CHECK: teq $[[R0]], $zero, 7
 ; CHECK: mfhi
   %rem = urem i64 %a, %b
   ret i64 %rem