<html><body style="word-wrap: break-word; -webkit-nbsp-mode: space; -webkit-line-break: after-white-space; "><br><div><div>On Oct 6, 2008, at 9:03 AM, Villmow, Micah wrote:</div><br class="Apple-interchange-newline"><blockquote type="cite"><span class="Apple-style-span" style="border-collapse: separate; color: rgb(0, 0, 0); font-family: Helvetica; font-size: 12px; font-style: normal; font-variant: normal; font-weight: normal; letter-spacing: normal; line-height: normal; orphans: 2; text-align: auto; text-indent: 0px; text-transform: none; white-space: normal; widows: 2; word-spacing: 0px; -webkit-border-horizontal-spacing: 0px; -webkit-border-vertical-spacing: 0px; -webkit-text-decorations-in-effect: none; -webkit-text-size-adjust: auto; -webkit-text-stroke-width: 0; "><div lang="EN-US" link="blue" vlink="purple"><o:smarttagtype namespaceuri="urn:schemas-microsoft-com:office:smarttags" name="City"><o:smarttagtype namespaceuri="urn:schemas-microsoft-com:office:smarttags" name="Street"><o:smarttagtype namespaceuri="urn:schemas-microsoft-com:office:smarttags" name="address"><o:smarttagtype namespaceuri="urn:schemas-microsoft-com:office:smarttags" name="place"><div class="Section1"><div style="margin-top: 0in; margin-right: 0in; margin-left: 0in; margin-bottom: 0.0001pt; font-size: 12pt; font-family: 'Times New Roman'; "><font size="2" face="Arial"><span style="font-size: 10pt; font-family: Arial; ">I am attempting to get indexing code generation working with my backend. However, it seems that the addresses being calculated is being multiplied by the width of the data type.<o:p></o:p></span></font></div><div style="margin-top: 0in; margin-right: 0in; margin-left: 0in; margin-bottom: 0.0001pt; font-size: 12pt; font-family: 'Times New Roman'; "><font size="2" face="Arial"><span style="font-size: 10pt; font-family: Arial; "><o:p> </o:p></span></font></div><div style="margin-top: 0in; margin-right: 0in; margin-left: 0in; margin-bottom: 0.0001pt; font-size: 12pt; font-family: 'Times New Roman'; "><font size="2" face="Arial"><span style="font-size: 10pt; font-family: Arial; ">define void @ test_input_index_constant_int(i32 addrspace(11)* %input, i32 addrspace(11)* %result) {<o:p></o:p></span></font></div><div style="margin-top: 0in; margin-right: 0in; margin-left: 0in; margin-bottom: 0.0001pt; font-size: 12pt; font-family: 'Times New Roman'; "><font size="2" face="Arial"><span style="font-size: 10pt; font-family: Arial; ">entry:<o:p></o:p></span></font></div><div style="margin-top: 0in; margin-right: 0in; margin-left: 0in; margin-bottom: 0.0001pt; font-size: 12pt; font-family: 'Times New Roman'; "><font size="2" face="Arial"><span style="font-size: 10pt; font-family: Arial; "> %input.addr = alloca i32 addrspace(11)* ; <i32 addrspace(11)**> [#uses=2]<o:p></o:p></span></font></div><div style="margin-top: 0in; margin-right: 0in; margin-left: 0in; margin-bottom: 0.0001pt; font-size: 12pt; font-family: 'Times New Roman'; "><font size="2" face="Arial"><span style="font-size: 10pt; font-family: Arial; "> %result.addr = alloca i32 addrspace(11)* ; <i32 addrspace(11)**> [#uses=2]<o:p></o:p></span></font></div><div style="margin-top: 0in; margin-right: 0in; margin-left: 0in; margin-bottom: 0.0001pt; font-size: 12pt; font-family: 'Times New Roman'; "><font size="2" face="Arial"><span style="font-size: 10pt; font-family: Arial; "> store i32 addrspace(11)* %input, i32 addrspace(11)** %input.addr<o:p></o:p></span></font></div><div style="margin-top: 0in; margin-right: 0in; margin-left: 0in; margin-bottom: 0.0001pt; font-size: 12pt; font-family: 'Times New Roman'; "><font size="2" face="Arial"><span style="font-size: 10pt; font-family: Arial; "> store i32 addrspace(11)* %result, i32 addrspace(11)** %result.addr<o:p></o:p></span></font></div><div style="margin-top: 0in; margin-right: 0in; margin-left: 0in; margin-bottom: 0.0001pt; font-size: 12pt; font-family: 'Times New Roman'; "><font size="2" face="Arial"><span style="font-size: 10pt; font-family: Arial; "> %tmp = load i32 addrspace(11)** %result.addr ; <i32 addrspace(11)*> [#uses=1]<o:p></o:p></span></font></div><div style="margin-top: 0in; margin-right: 0in; margin-left: 0in; margin-bottom: 0.0001pt; font-size: 12pt; font-family: 'Times New Roman'; "><font size="2" face="Arial"><span style="font-size: 10pt; font-family: Arial; "> %tmp1 = load i32 addrspace(11)** %input.addr ; <i32 addrspace(11)*> [#uses=1]<o:p></o:p></span></font></div><div style="margin-top: 0in; margin-right: 0in; margin-left: 0in; margin-bottom: 0.0001pt; font-size: 12pt; font-family: 'Times New Roman'; "><font size="2" face="Arial"><span style="font-size: 10pt; font-family: Arial; "> <span class="Apple-converted-space"> </span><b><span style="font-weight: bold; ">%arrayidx = getelementptr i32 addrspace(11)* %tmp1, i32 23 ; <i32 addrspace(11)*> [#uses=1]<o:p></o:p></span></b></span></font></div><div style="margin-top: 0in; margin-right: 0in; margin-left: 0in; margin-bottom: 0.0001pt; font-size: 12pt; font-family: 'Times New Roman'; "><font size="2" face="Arial"><span style="font-size: 10pt; font-family: Arial; "> %tmp2 = load i32 addrspace(11)* %arrayidx ; <i32> [#uses=1]<o:p></o:p></span></font></div><div style="margin-top: 0in; margin-right: 0in; margin-left: 0in; margin-bottom: 0.0001pt; font-size: 12pt; font-family: 'Times New Roman'; "><font size="2" face="Arial"><span style="font-size: 10pt; font-family: Arial; "> store i32 %tmp2, i32 addrspace(11)* %tmp<o:p></o:p></span></font></div><div style="margin-top: 0in; margin-right: 0in; margin-left: 0in; margin-bottom: 0.0001pt; font-size: 12pt; font-family: 'Times New Roman'; "><font size="2" face="Arial"><span style="font-size: 10pt; font-family: Arial; "> ret void<o:p></o:p></span></font></div><div style="margin-top: 0in; margin-right: 0in; margin-left: 0in; margin-bottom: 0.0001pt; font-size: 12pt; font-family: 'Times New Roman'; "><font size="2" face="Arial"><span style="font-size: 10pt; font-family: Arial; ">}<o:p></o:p></span></font></div><div style="margin-top: 0in; margin-right: 0in; margin-left: 0in; margin-bottom: 0.0001pt; font-size: 12pt; font-family: 'Times New Roman'; "><font size="2" face="Arial"><span style="font-size: 10pt; font-family: Arial; "><o:p> </o:p></span></font></div><div style="margin-top: 0in; margin-right: 0in; margin-left: 0in; margin-bottom: 0.0001pt; font-size: 12pt; font-family: 'Times New Roman'; "><font size="2" face="Arial"><span style="font-size: 10pt; font-family: Arial; ">The value 23 in the getelementptr is being multiplied by 4 bytes and the generated code is the value 96. However, I don’t want this multiplication to occur and I cannot figure out how to divide the immediate by 4 when lowering the Add instruction that is linked to a load/store operation.<o:p></o:p></span></font></div><div style="margin-top: 0in; margin-right: 0in; margin-left: 0in; margin-bottom: 0.0001pt; font-size: 12pt; font-family: 'Times New Roman'; "><font size="2" face="Arial"><span style="font-size: 10pt; font-family: Arial; "><o:p> </o:p></span></font></div><div style="margin-top: 0in; margin-right: 0in; margin-left: 0in; margin-bottom: 0.0001pt; font-size: 12pt; font-family: 'Times New Roman'; "><font size="2" face="Arial"><span style="font-size: 10pt; font-family: Arial; ">So my question is, how do I modified a immediate constant value from an SDValue struct? If that is not possible, what section of code do I need to modify to get LLVM to stop multiplying the index by the data size.</span></font></div></div></o:smarttagtype></o:smarttagtype></o:smarttagtype></o:smarttagtype></div></span></blockquote><br></div><div>Hi Micah,</div><div><br></div><div>You really don't want to change the semantics of the getelementptr instruction. Instead, you should change whatever is generating this instruction to generate the appropriate code. If you want to do an offset in terms of bytes, the standard way to do it is to bitcast your pointer to "i8*" and then do a getelementptr from that pointer,</div><div><br></div><div>-Chris</div></body></html>