Commit Graph

8615 Commits

Author SHA1 Message Date
Tom Stellard
3f5d63b956 R600: Add support for 24-bit MUL instructions
Reviewed-by: Vincent Lejeune <vljn at ovi.com>

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@186922 91177308-0d34-0410-b5e6-96231b3b80d8
2013-07-23 01:48:42 +00:00
Tom Stellard
eb643b9b37 R600: Improve support for < 32-bit loads
Reviewed-by: Vincent Lejeune <vljn at ovi.com>

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@186921 91177308-0d34-0410-b5e6-96231b3b80d8
2013-07-23 01:48:35 +00:00
Tom Stellard
58d3335cb9 R600: Move CONST_ADDRESS folding into AMDGPUDAGToDAGISel::Select()
This increases the number of opportunites we have for folding.  With the
previous implementation we were unable to fold into any instructions
other than the first when multiple instructions were selected from a
single SDNode.

Reviewed-by: Vincent Lejeune <vljn at ovi.com>

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@186919 91177308-0d34-0410-b5e6-96231b3b80d8
2013-07-23 01:48:24 +00:00
Tom Stellard
a7eea0568c R600: Use KCache for kernel arguments
Reviewed-by: Vincent Lejeune <vljn at ovi.com>

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@186918 91177308-0d34-0410-b5e6-96231b3b80d8
2013-07-23 01:48:18 +00:00
Tom Stellard
f502c292f6 R600: Use the same compute kernel calling convention for all GPUs
A side-effect of this is that now the compiler expects kernel arguments
to be 4-byte aligned.

Reviewed-by: Vincent Lejeune <vljn at ovi.com>

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@186916 91177308-0d34-0410-b5e6-96231b3b80d8
2013-07-23 01:48:05 +00:00
Tom Stellard
5864284d71 R600: Use correct LoadExtType when lowering kernel arguments
Reviewed-by: Vincent Lejeune <vljn at ovi.com>

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@186915 91177308-0d34-0410-b5e6-96231b3b80d8
2013-07-23 01:47:58 +00:00
Tom Stellard
2bb20fd2bf R600: Clean up extended load patterns
Reviewed-by: Vincent Lejeune <vljn at ovi.com>

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@186914 91177308-0d34-0410-b5e6-96231b3b80d8
2013-07-23 01:47:52 +00:00
Tom Stellard
d7a472c9c6 R600: Expand vector FNEG
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@186913 91177308-0d34-0410-b5e6-96231b3b80d8
2013-07-23 01:47:46 +00:00
Manman Ren
0e29eeec27 Debug Info Finder: use processDeclare and processValue to list debug info
MDNodes used by DbgDeclareInst and DbgValueInst.

Another 16 testing cases failed and they are disabled with
-disable-debug-info-verifier.
A total of 34 cases are disabled with -disable-debug-info-verifier and will be
corrected.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@186902 91177308-0d34-0410-b5e6-96231b3b80d8
2013-07-23 00:22:51 +00:00
Mihai Popa
0226538292 This adds range checking for "ldr Rn, [pc, #imm]" Thumb
instructions. With this patch:

1. ldr.n is recognized as mnemonic for the short encoding
2. ldr.w is recognized as menmonic for the long encoding
3. ldr will map to either short or long encodings depending on the size of the offset

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@186831 91177308-0d34-0410-b5e6-96231b3b80d8
2013-07-22 15:49:36 +00:00
Justin Holewinski
3a8ee4ffd7 [NVPTX] Use approximate FP ops when unsafe-fp-math is used, and append
.ftz to instructions if the nvptx-f32ftz attribute is set to "true"

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@186820 91177308-0d34-0410-b5e6-96231b3b80d8
2013-07-22 12:18:04 +00:00
Lang Hames
7b61a70193 Refactor AnalyzeBranch on ARM. The previous version did not always analyze
indirect branches correctly. Under some circumstances, this led to the deletion
of basic blocks that were the destination of indirect branches. In that case it
left indirect branches to nowhere in the code.

This patch replaces, and is more general than either of the previous fixes for
indirect-branch-analysis issues, r181161 and r186461.

For other branches (not indirect) this refactor should have *almost* identical
behavior to the previous version. There are some corner cases where this
refactor is able to analyze blocks that the previous version could not (e.g.
this necessitated the update to thumb2-ifcvt2.ll). 

<rdar://problem/14464830>



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@186735 91177308-0d34-0410-b5e6-96231b3b80d8
2013-07-19 23:52:47 +00:00
Vincent Lejeune
272458bd06 R600: Don't emit empty then clause and use alu_pop_after
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@186725 91177308-0d34-0410-b5e6-96231b3b80d8
2013-07-19 21:45:15 +00:00
Rafael Espindola
7096831971 s/compiler_used/compiler.used/.
We were incorrectly using compiler_used instead of compiler.used. Unfortunately
the passes using the broken name had tests also using the broken name.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@186705 91177308-0d34-0410-b5e6-96231b3b80d8
2013-07-19 18:44:51 +00:00
Richard Sandiford
6dae7ae765 [SystemZ] Add tests for ALHSIK and ALGHSIK
The insn definitions themselves crept into r186689, sorry.
This should be the last of the distinct-ops instructions.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@186690 91177308-0d34-0410-b5e6-96231b3b80d8
2013-07-19 16:44:32 +00:00
Richard Sandiford
c7c7e1502a [SystemZ] Add ALRK, AGLRK, SLRK and SGLRK
Follows the same lines as r186686, but much more limited, since we only
use ADD LOGICAL for multi-i64 additions.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@186689 91177308-0d34-0410-b5e6-96231b3b80d8
2013-07-19 16:37:00 +00:00
Richard Sandiford
70d3e71f2e [SystemZ] Add AHIK and AGHIK
I did these as a separate patch because it uses a slightly different
form of RIE layout.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@186687 91177308-0d34-0410-b5e6-96231b3b80d8
2013-07-19 16:32:12 +00:00
Richard Sandiford
dc05e0bff6 [SystemZ] Add ARK, AGRK, SRK and SGRK
The testsuite changes follow the same lines as for r186683.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@186686 91177308-0d34-0410-b5e6-96231b3b80d8
2013-07-19 16:26:39 +00:00
Richard Sandiford
52b2774577 [SystemZ] Add NGRK, OGRK and XGRK
Like r186683, but for 64 bits.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@186685 91177308-0d34-0410-b5e6-96231b3b80d8
2013-07-19 16:24:22 +00:00
Richard Sandiford
db92fb0716 [SystemZ] Add NRK, ORK and XRK
The atomic tests assume the two-operand forms, so I've restricted them to z10.

Running and-01.ll, or-01.ll and xor-01.ll for z196 as well as z10 shows why
using convertToThreeAddress() is better than exposing the three-operand forms
first and then converting back to two operands where possible (which is what
I'd originally tried).  Using the three-operand form first stops us from
taking advantage of NG, OG and XG for spills.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@186683 91177308-0d34-0410-b5e6-96231b3b80d8
2013-07-19 16:21:55 +00:00
Richard Sandiford
93c2125c39 [SystemZ] Use SLLK, SRLK and SRAK for codegen
This patch uses the instructions added in r186680 for codegen.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@186681 91177308-0d34-0410-b5e6-96231b3b80d8
2013-07-19 16:12:08 +00:00
Manman Ren
98cd02622d Try to appease the bots.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@186653 91177308-0d34-0410-b5e6-96231b3b80d8
2013-07-19 04:56:51 +00:00
Andrew Trick
8594c2377d MI Sched: test case fix for previous checkin.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@186635 91177308-0d34-0410-b5e6-96231b3b80d8
2013-07-19 00:31:31 +00:00
Manman Ren
cd26257c85 Debug Info: enable verifying by default and disable testing cases that fail.
1> Use DebugInfoFinder to find debug info MDNodes.
2> Add disable-debug-info-verifier to disable verifying debug info.
3> Disable verifying for testing cases that fail (will update the testing cases
   later on).
4> MDNodes generated by clang can have empty filename for TAG_inheritance and
   TAG_friend, so DIType::Verify is modified accordingly.

Note that DebugInfoFinder does not list all debug info MDNode.
For example, clang can generate:
metadata !{i32 786468}, which will fail to verify.
This MDNode is used by debug info but not included in DebugInfoFinder.
This MDNode is generated as a temporary node in DIBuilder::createFunction
  Value *TElts[] = { GetTagConstant(VMContext, DW_TAG_base_type) };
  MDNode::getTemporary(VMContext, TElts)


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@186634 91177308-0d34-0410-b5e6-96231b3b80d8
2013-07-19 00:31:03 +00:00
Stephen Lin
cf2ab764db Update to more CodeGen tests to use CHECK-LABEL for labels corresponding to function definitions for more informative error messages. No functionality change.
All changes were made by the following bash script:

  find test/CodeGen -name "*.ll" | \
  while read NAME; do
    echo "$NAME"
    grep -q "^; *RUN: *llc.*debug" $NAME && continue
    grep -q "^; *RUN:.*llvm-objdump" $NAME && continue
    grep -q "^; *RUN: *opt.*" $NAME && continue
    TEMP=`mktemp -t temp`
    cp $NAME $TEMP
    sed -n "s/^define [^@]*@\([A-Za-z0-9_]*\)(.*$/\1/p" < $NAME | \
    while read FUNC; do
      sed -i '' "s/;\([A-Za-z0-9_-]*\)\([A-Za-z0-9_-]*\):\( *\)$FUNC[:]* *\$/;\1\2-LABEL:\3$FUNC:/g" $TEMP
    done
    sed -i '' "s/;\(.*\)-LABEL-LABEL:/;\1-LABEL:/" $TEMP
    sed -i '' "s/;\(.*\)-NEXT-LABEL:/;\1-NEXT:/" $TEMP
    sed -i '' "s/;\(.*\)-NOT-LABEL:/;\1-NOT:/" $TEMP
    sed -i '' "s/;\(.*\)-DAG-LABEL:/;\1-DAG:/" $TEMP
    mv $TEMP $NAME
  done

This script catches a superset of the cases caught by the script associated with commit r186280. It initially found some false positives due to unusual constructs in a minority of tests; all such cases were disambiguated first in commit r186621.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@186624 91177308-0d34-0410-b5e6-96231b3b80d8
2013-07-18 22:47:09 +00:00
Stephen Lin
771e0ab32a Disambiguate function names in some CodeGen tests. (Some tests were using function names that also were names of instructions and/or doing other unusual things that were making the test not amenable to otherwise scriptable pattern matching.) No functionality change.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@186621 91177308-0d34-0410-b5e6-96231b3b80d8
2013-07-18 22:29:15 +00:00
Tom Stellard
4e518fd941 R600/SI: Fix crash with VSELECT
https://bugs.freedesktop.org/show_bug.cgi?id=66175

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@186616 91177308-0d34-0410-b5e6-96231b3b80d8
2013-07-18 21:43:53 +00:00
Tom Stellard
ac85f3f65c R600/SI: Add support for v2f32 loads
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@186615 91177308-0d34-0410-b5e6-96231b3b80d8
2013-07-18 21:43:48 +00:00
Tom Stellard
fc047278c1 R600/SI: Add support for v2f32 stores
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@186614 91177308-0d34-0410-b5e6-96231b3b80d8
2013-07-18 21:43:42 +00:00
Tom Stellard
f5660aab41 R600: Expand VSELECT for all types
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@186613 91177308-0d34-0410-b5e6-96231b3b80d8
2013-07-18 21:43:35 +00:00
Stephen Lin
be9dd85f44 Update to CodeGen tests to use CHECK-LABEL for labels corresponding to function definitions for more informative error messages. No functionality change.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@186594 91177308-0d34-0410-b5e6-96231b3b80d8
2013-07-18 18:35:22 +00:00
Joey Gouly
f75a964173 Forgot 'svn add' again, sorry!
Tests for r186574.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@186580 91177308-0d34-0410-b5e6-96231b3b80d8
2013-07-18 13:17:26 +00:00
Richard Sandiford
722a26d63e [SystemZ] Use RNSBG
This should be the last of the R.SBG patches for now.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@186573 91177308-0d34-0410-b5e6-96231b3b80d8
2013-07-18 10:40:35 +00:00
Richard Sandiford
9dffd71d0a [SystemZ] Generalize RxSBG SRA case
The original code only folded SRA into ROTATE ... SELECTED BITS
if there was no outer shift.  This patch splits out that check
and generalises it slightly.  The extra cases aren't really that
interesting, but this is paving the way for RNSBG support.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@186571 91177308-0d34-0410-b5e6-96231b3b80d8
2013-07-18 10:14:55 +00:00
Richard Sandiford
30a132f767 [SystemZ] Use RXSBG
Extend the previous R.SBG patches to handle XORs.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@186570 91177308-0d34-0410-b5e6-96231b3b80d8
2013-07-18 10:06:15 +00:00
Craig Topper
fe754512dc Fix copy and paste bug from r186491 to make v2f64 use MOVAPD/MOVUPD as it should.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@186566 91177308-0d34-0410-b5e6-96231b3b80d8
2013-07-18 07:16:44 +00:00
Hal Finkel
aad2a72c28 PPC: Support dynamic allocas with large alignment
Support for dynamic stack alignments in the PPC backend has been unfinished, in
part because it depends on dynamic stack realignment (which I only just
recently implemented fully). Now we can also support dynamic allocas with
higher than the default target stack alignment (16 bytes).

In order to round-up the requested size to the maximum requested alignment, we
need an additional register to hold the rounded-up size. We're already using one
scavenged register to hold the previous stack-pointer value (which needs to be
stored with the signal-safe stdux update), and so when we have dynamic allocas
and a large alignment, we allocate two emergency spill slots for the scavenger.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@186562 91177308-0d34-0410-b5e6-96231b3b80d8
2013-07-18 04:28:21 +00:00
Hal Finkel
0541722de4 PPC: Add base-pointer support to builtin setjmp/longjmp
First, this changes the base-pointer implementation to remove an unnecessary
complication (and one that is incompatible with how builtin SjLj is
implemented): instead of using r31 as the base pointer when it is not needed as
a frame pointer, now the base pointer will always be r30 when needed.

Second, we introduce another pseudo register, BP, which is used just like the FP
pseudo register to refer to the base register before we know for certain what
register it will be.

Third, we now save BP into the jmp_buf, and restore r30 from that slot in
longjmp.  If the function that called setjmp did not use a base pointer, then
r30 will be overwritten by the setjmp-calling-function's restore code. FP
restoration (which is restored into r31) works the same way.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@186545 91177308-0d34-0410-b5e6-96231b3b80d8
2013-07-17 23:50:51 +00:00
Joey Gouly
c88ac4a344 Add the tests that I forgot to 'svn add' with my previous commit (r186504).
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@186506 91177308-0d34-0410-b5e6-96231b3b80d8
2013-07-17 14:03:49 +00:00
Richard Osborne
dcc4207a00 [XCore] Ensure implicit operands aren't lost on the return instruction.
Patch by Robert Lytton.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@186500 91177308-0d34-0410-b5e6-96231b3b80d8
2013-07-17 10:58:37 +00:00
Craig Topper
e0364b64d1 Make x86 fast-isel correctly choose between aligned and unaligned operations for vector stores. Fixes PR16640.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@186491 91177308-0d34-0410-b5e6-96231b3b80d8
2013-07-17 05:57:45 +00:00
Hal Finkel
8d7435e9b1 PPC: Add CTR-register clobber to builtin setjmp
Because the builtin longjmp implementation uses a CTR-based indirect jump, when
the control flow arrives at the builtin setjmp call, the CTR register has
necessarily been clobbered. Correspondingly, this adds CTR to the list of
implicit definitions of the builtin setjmp pseudo instruction.

We don't need to add CTR to the implicit definitions of builtin longjmp
because, even though it does clobber the CTR register, the control flow cannot
return to inside the loop unless there is also a builtin setjmp call.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@186488 91177308-0d34-0410-b5e6-96231b3b80d8
2013-07-17 05:35:44 +00:00
Hal Finkel
fe47bf8fa0 PPC: Implement base pointer and stack realignment
This builds on some frame-lowering code that has existed since 2005 (r24224)
but was disabled in 2008 (r48188) because it needed base pointer support to
function correctly. This implementation follows the strategy suggested by Dale
Johannesen in r48188 where the following comment was added:

  This does not currently work, because the delta between old and new stack
  pointers is added to offsets that reference incoming parameters after the
  prolog is generated, and the code that does that doesn't handle a variable
  delta.  You don't want to do that anyway; a better approach is to reserve
  another register that retains to the incoming stack pointer, and reference
  parameters relative to that.

And now we do exactly that. If we don't need a frame pointer, then we use r31
as a base pointer. If we do need a frame pointer, then we use r30 as a base
pointer. The base pointer retains the value of the stack pointer before it was
decremented in the prologue. We then use the base pointer to resolve all
negative frame indicies. The basic scheme follows that for base pointers in the
X86 backend.

We use a base pointer when we need to dynamically realign the incoming stack
pointer. This currently applies only to static objects (dynamic allocas with
large alignments, and base-pointer support in SjLj lowering will come in future
commits).

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@186478 91177308-0d34-0410-b5e6-96231b3b80d8
2013-07-17 00:45:52 +00:00
NAKAMURA Takumi
63e22afdce llvm/test/CodeGen/X86/vec_setcc.ll: Add explicit -mtriple=x86_64-unknown-unknown to satisfy win32-targeted configuration.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@186477 91177308-0d34-0410-b5e6-96231b3b80d8
2013-07-17 00:42:37 +00:00
Benjamin Kramer
1a9c39e52a Finally, force the target for this test. Should unbreak non-x86 buildbots.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@186445 91177308-0d34-0410-b5e6-96231b3b80d8
2013-07-16 19:22:07 +00:00
Benjamin Kramer
f97337daa0 Label names also differ between platforms. Use a relaxed regex.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@186442 91177308-0d34-0410-b5e6-96231b3b80d8
2013-07-16 18:54:21 +00:00
Benjamin Kramer
a217a87253 Fix test not to fail when the target doesn't use leading underscores on symbols.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@186439 91177308-0d34-0410-b5e6-96231b3b80d8
2013-07-16 18:42:01 +00:00
Manman Ren
1872b589ff Cleanup testing case by using a shorter name for types.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@186436 91177308-0d34-0410-b5e6-96231b3b80d8
2013-07-16 18:26:48 +00:00
Juergen Ributzka
b95e0f6f2f [X86] Use min/max to optimze unsigend vector comparison on X86
Use PMIN/PMAX for UGE/ULE vector comparions to reduce the number of required
instructions. This trick also works for UGT/ULT, but there is no advantage in
doing so. It wouldn't reduce the number of instructions and it would actually
reduce performance.

Reviewer: Ben

radar:5972691



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@186432 91177308-0d34-0410-b5e6-96231b3b80d8
2013-07-16 18:20:45 +00:00
Ulrich Weigand
f0d0a1681a [APFloat] PR16573: Avoid losing mantissa bits in ppc_fp128 to double truncation
When truncating to a format with fewer mantissa bits, APFloat::convert
will perform a right shift of the mantissa by the difference of the
precision of the two formats.  Usually, this will result in just the
mantissa bits needed for the target format.

One special situation is if the input number is denormal.  In this case,
the right shift may discard significant bits.  This is usually not a
problem, since truncating a denormal usually results in zero (underflow)
after normalization anyway, since the result format's exponent range is
usually smaller than the target format's.

However, there is one case where the latter property does not hold:
when truncating from ppc_fp128 to double.  In particular, truncating
a ppc_fp128 whose first double of the pair is denormal should result
in just that first double, not zero.  The current code however
performs an excessive right shift, resulting in lost result bits.
This is then caught in the APFloat::normalize call performed by
APFloat::convert and causes an assertion failure.

This patch checks for the scenario of truncating a denormal, and
attempts to (possibly partially) replace the initial mantissa
right shift by decrementing the exponent, if doing so will still
result in a valid *target format* exponent.


Index: test/CodeGen/PowerPC/pr16573.ll
===================================================================
--- test/CodeGen/PowerPC/pr16573.ll	(revision 0)
+++ test/CodeGen/PowerPC/pr16573.ll	(revision 0)
@@ -0,0 +1,11 @@
+; RUN: llc < %s | FileCheck %s
+
+target triple = "powerpc64-unknown-linux-gnu"
+
+define double @test() {
+  %1 = fptrunc ppc_fp128 0xM818F2887B9295809800000000032D000 to double
+  ret double %1
+}
+
+; CHECK: .quad -9111018957755033591
+
Index: lib/Support/APFloat.cpp
===================================================================
--- lib/Support/APFloat.cpp	(revision 185817)
+++ lib/Support/APFloat.cpp	(working copy)
@@ -1956,6 +1956,23 @@
     X86SpecialNan = true;
   }
 
+  // If this is a truncation of a denormal number, and the target semantics
+  // has larger exponent range than the source semantics (this can happen
+  // when truncating from PowerPC double-double to double format), the
+  // right shift could lose result mantissa bits.  Adjust exponent instead
+  // of performing excessive shift.
+  if (shift < 0 && isFiniteNonZero()) {
+    int exponentChange = significandMSB() + 1 - fromSemantics.precision;
+    if (exponent + exponentChange < toSemantics.minExponent)
+      exponentChange = toSemantics.minExponent - exponent;
+    if (exponentChange < shift)
+      exponentChange = shift;
+    if (exponentChange < 0) {
+      shift -= exponentChange;
+      exponent += exponentChange;
+    }
+  }
+
   // If this is a truncation, perform the shift before we narrow the storage.
   if (shift < 0 && (isFiniteNonZero() || category==fcNaN))
     lostFraction = shiftRight(significandParts(), oldPartCount, -shift);


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@186409 91177308-0d34-0410-b5e6-96231b3b80d8
2013-07-16 13:03:25 +00:00