[lld] r365930 - [WebAssembly] i32.const operands should be signed

[Thomas Lively via llvm-commits]

Author: tlively
Date: Fri Jul 12 10:55:07 2019
New Revision: 365930

URL: http://llvm.org/viewvc/llvm-project?rev=365930&view=rev
Log:
[WebAssembly] i32.const operands should be signed

Summary:
This was causing large addresses to be emitted as negative numbers,
which rightfully caused crashes in binaryen.

Reviewers: aheejin, dschuff

Subscribers: sbc100, jgravelle-google, sunfish, llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D64612

Modified:
    lld/trunk/test/wasm/data-segments.ll
    lld/trunk/wasm/Writer.cpp

Modified: lld/trunk/test/wasm/data-segments.ll
URL: http://llvm.org/viewvc/llvm-project/lld/trunk/test/wasm/data-segments.ll?rev=365930&r1=365929&r2=365930&view=diff
==============================================================================
--- lld/trunk/test/wasm/data-segments.ll (original)
+++ lld/trunk/test/wasm/data-segments.ll Fri Jul 12 10:55:07 2019
@@ -41,7 +41,7 @@ target triple = "wasm32-unknown-unknown"
 
 @a = hidden global [6 x i8] c"hello\00", align 1
 @b = hidden global [8 x i8] c"goodbye\00", align 1
- at c = hidden global [9 x i8] c"whatever\00", align 1
+ at c = hidden global [10000 x i8] zeroinitializer, align 1
 @d = hidden global i32 42, align 4
 
 @e = private constant [9 x i8] c"constant\00", align 1
@@ -59,14 +59,21 @@ target triple = "wasm32-unknown-unknown"
 ; ACTIVE-NEXT:      - SectionOffset:   7
 ; ACTIVE-NEXT:        InitFlags:       0
 ; ACTIVE-NEXT:        Offset:
-; ACTIVE-NEXT:        Opcode:          I32_CONST
-; ACTIVE-NEXT:        Value:           1024
-; ACTIVE-NEXT:        Content:         68656C6C6F00676F6F6462796500776861746576657200002A000000
-; ACTIVE-NEXT:      - SectionOffset:   41
+; ACTIVE-NEXT:          Opcode:          I32_CONST
+; ACTIVE-NEXT:          Value:           1024
+; ACTIVE-NEXT:        Content:         68656C6C6F00676F6F646279650000002A000000
+; ACTIVE-NEXT:      - SectionOffset:   34
 ; ACTIVE-NEXT:        InitFlags:       0
 ; ACTIVE-NEXT:        Offset:
-; ACTIVE-NEXT:        Opcode:          I32_CONST
-; ACTIVE-NEXT:        Value:           1052
+; ACTIVE-NEXT:          Opcode:          I32_CONST
+; ACTIVE-NEXT:          Value:           1044
+; ACTIVE-NEXT:        Content:         '0000000000
+; ACTIVE-SAME:                           0000000000'
+; ACTIVE-NEXT:      - SectionOffset:   10041
+; ACTIVE-NEXT:        InitFlags:       0
+; ACTIVE-NEXT:        Offset:
+; ACTIVE-NEXT:          Opcode:          I32_CONST
+; ACTIVE-NEXT:          Value:           11044
 ; ACTIVE-NEXT:        Content:         636F6E7374616E74000000002B
 ; ACTIVE-NEXT:  - Type:            CUSTOM
 ; ACTIVE-NEXT:    Name:            name
@@ -81,13 +88,17 @@ target triple = "wasm32-unknown-unknown"
 ; PASSIVE-NEXT:        Body:            10010B
 ; PASSIVE-NEXT:      - Index:           1
 ; PASSIVE-NEXT:        Locals:          []
-; PASSIVE-NEXT:        Body:            4180084100411CFC080000FC0900419C084100410DFC080100FC09010B
+; PASSIVE-NEXT:        Body:            41800841004114FC080000FC090041940841004190CE00FC080100FC090141A4D6004100410DFC080200FC09020B
 ; PASSIVE-NEXT:  - Type:            DATA
 ; PASSIVE-NEXT:    Segments:
 ; PASSIVE-NEXT:      - SectionOffset:   3
 ; PASSIVE-NEXT:        InitFlags:       1
-; PASSIVE-NEXT:        Content:         68656C6C6F00676F6F6462796500776861746576657200002A000000
-; PASSIVE-NEXT:      - SectionOffset:   33
+; PASSIVE-NEXT:        Content:         68656C6C6F00676F6F646279650000002A000000
+; PASSIVE-NEXT:      - SectionOffset:   26
+; PASSIVE-NEXT:        InitFlags:       1
+; PASSIVE-NEXT:        Content:         '0000000000
+; PASSIVE-SAME:                           0000000000'
+; PASSIVE-NEXT:      - SectionOffset:   10028
 ; PASSIVE-NEXT:        InitFlags:       1
 ; PASSIVE-NEXT:        Content:         636F6E7374616E74000000002B
 ; PASSIVE-NEXT:  - Type:            CUSTOM

Modified: lld/trunk/wasm/Writer.cpp
URL: http://llvm.org/viewvc/llvm-project/lld/trunk/wasm/Writer.cpp?rev=365930&r1=365929&r2=365930&view=diff
==============================================================================
--- lld/trunk/wasm/Writer.cpp (original)
+++ lld/trunk/wasm/Writer.cpp Fri Jul 12 10:55:07 2019
@@ -658,13 +658,13 @@ void Writer::createInitMemoryFunction()
       if (s->initFlags & WASM_SEGMENT_IS_PASSIVE) {
         // destination address
         writeU8(os, WASM_OPCODE_I32_CONST, "i32.const");
-        writeUleb128(os, s->startVA, "destination address");
+        writeSleb128(os, s->startVA, "destination address");
         // source segment offset
         writeU8(os, WASM_OPCODE_I32_CONST, "i32.const");
-        writeUleb128(os, 0, "segment offset");
+        writeSleb128(os, 0, "segment offset");
         // memory region size
         writeU8(os, WASM_OPCODE_I32_CONST, "i32.const");
-        writeUleb128(os, s->size, "memory region size");
+        writeSleb128(os, s->size, "memory region size");
         // memory.init instruction
         writeU8(os, WASM_OPCODE_MISC_PREFIX, "bulk-memory prefix");
         writeUleb128(os, WASM_OPCODE_MEMORY_INIT, "MEMORY.INIT");